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Protein / target

Thymidylate synthase

Encoded byTYMSP04818Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
9
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

MRNA regulatory element binding translation repressor

Strongest disease association

Dyskeratosis congenita, digenic

Via encoding gene TYMS · Genetic evidence · score 0.82

Therapeutic position

Established drug target

Small molecules

Research activity

Emerging research

1 papers · latest 2020

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function overview

Catalyzes the reductive methylation of 2'-deoxyuridine 5'-monophosphate (dUMP) to thymidine 5'-monophosphate (dTMP), using the cosubstrate, 5,10- methylenetetrahydrofolate (CH2H4folate) as a 1-carbon donor and reductant and contributes to the mitochondrial and nuclear de novo thymidylate biosynthesi…

View complete UniProt function annotation

Catalyzes the reductive methylation of 2'-deoxyuridine 5'-monophosphate (dUMP) to thymidine 5'-monophosphate (dTMP), using the cosubstrate, 5,10- methylenetetrahydrofolate (CH2H4folate) as a 1-carbon donor and reductant and contributes to the mitochondrial and nuclear de novo thymidylate biosynthesis pathway

Subcellular location

NucleusCytoplasmMitochondrionMitochondrion matrixMitochondrion inner membrane
Domains and Gene Ontology detail (19)

Gene Ontology

  • Ccytoplasm
  • Ccytosol
  • Cmitochondrial inner membrane
  • Cmitochondrial matrix
  • Cmitochondrion
  • Cnucleus
  • Creplication fork
  • Ffolic acid binding
  • FmRNA regulatory element binding translation repressor activity
  • Fsequence-specific mRNA binding
  • Fthymidylate synthase activity
  • P'de novo' pyrimidine nucleobase biosynthetic process

313 aa · 36 kDa · 3 isoforms

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

View underlying pathways (2)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

DHFR2DHFRDCTDSHMT1DTYMKSHMT2TK2DUTMTHFD2FPGSTYMS

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Approved medicines with mapped indications

4 medicines · 8 areas

Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.

Adenocarcinoma1 medicine
Breast Neoplasms1 medicine
Colonic Neoplasms1 medicine
Colorectal Neoplasms1 medicine
Keratosis, Actinic1 medicine
Mesothelioma1 medicine
Stomach Neoplasms1 medicine

9 medicines meet Open Targets' target-level approved-medicine definition; the 4 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

4

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

Fluorouracil
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Indicated for Adenocarcinoma, Keratosis, Actinic, Neoplasms

Direct interaction with this protein · Only this protein recorded as a target

pemetrexed
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Indicated for Mesothelioma, Neoplasms

Direct interaction with this protein · 1 of 3 recorded protein targets — narrow recorded profile

capecitabine
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Indicated for Breast Neoplasms, Colonic Neoplasms, Colorectal Neoplasms, Stomach Neoplasms

Direct interaction with this protein · Only this protein recorded as a target

raltitrexed
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Indicated for Neoplasms

Direct interaction with this protein · Only this protein recorded as a target

ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene TYMS

Gene-level evidence surfaced through the gene TYMSthat encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

Dyskeratosis congenita, digenic
0.82Well supported

Genetic evidence dominant · Open Targets 0.66

Dyskeratosis congenita
0.79Well supported

Genetic evidence dominant · Open Targets 0.60

Carcinoma, Non-Small-Cell Lung
0.79Well supported

Clinical evidence dominant · Open Targets 0.63

Breast Neoplasms
0.77Well supported

Clinical evidence dominant · Open Targets 0.62

Colorectal Neoplasms
0.76Well supported

Clinical evidence dominant · Open Targets 0.61

View evidence synthesis (5)
Dyskeratosis congenita, digenicWell supported
0.82
agreement 0.700.94
Genetic100%Genetic literaturedup

Open Targets aggregate 0.66 · 1 independent evidence family · 1 not counted as duplicate

Dyskeratosis congenitaWell supported
0.79
agreement 0.650.93
Genetic97%Literature3%

Open Targets aggregate 0.60 · 2 independent evidence families

Carcinoma, Non-Small-Cell LungWell supported
0.79
agreement 0.650.92
Clinical80%Literature16%RNA expression4%

Open Targets aggregate 0.63 · 3 independent evidence families

Breast NeoplasmsWell supported
0.77
agreement 0.640.91
Clinical82%Literature15%RNA expression4%

Open Targets aggregate 0.62 · 3 independent evidence families

Colorectal NeoplasmsWell supported
0.76
agreement 0.600.92
Clinical86%Literature14%

Open Targets aggregate 0.61 · 2 independent evidence families

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.

Show all associations
Dyskeratosis congenita, digenic0.66
Carcinoma, Non-Small-Cell Lung0.63
Breast Neoplasms0.62
Colorectal Neoplasms0.61
Colonic Neoplasms0.60
Neoplasms0.60
Dyskeratosis congenita0.60
Mesothelioma0.59
Stomach Neoplasms0.58

Drug development

11 compounds recorded · 9 approved · 2 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 4 drugs that target this protein in Forefront's canonical graph (4 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (10)
OSI-7904Phase 2
CAPECITABINEApproval
PEMETREXED DISODIUMApproval
RALTITREXEDApproval
NOLATREXEDPhase 3
DOXIFLURIDINEApproval
TEGAFURApproval
PEMETREXEDApproval
FLOXURIDINEApproval
FLUOROURACILApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesStrong

Approved Drug and Structure with Ligand support this modality.

Protein degradersEmerging

Feasibility evidence (uniprot ubiquitination and database ubiquitination) — no clinical-stage drug of this modality recorded.

View underlying tractability evidence (8)
SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · High-Quality PocketSM · Druggable FamilyPR · UniProt UbiquitinationPR · Database UbiquitinationPR · Small Molecule Binder

Raw Open Targets tractability assessment buckets, by modality.

Safety-related annotations

discontinuation of therapy due to severe toxicityClinPGxastheniaClinPGxdrug toxicityClinPGxnausea and vomitingClinPGxside effectsClinPGxdiarrheaClinPGx

Terms indexed against this target in Open Targets' safety data, with their datasource. These are annotations, not causal claims: the direction of effect (whether activation or inhibition is implicated), species and evidence strength are not captured here, so an entry does not mean that modulating this target is known to cause that condition.

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

View all trials (26)

RECRUITING · via capecitabine · NCT07456852

NOT_YET_RECRUITING · via Fluorouracil · NCT06370754

ClinicalTrials.gov via the drug-target graph.

What's happening now

12

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 3 drugs that target this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  1. Trial status changed2026-08-25

    Phase I/II Study of Neoadjuvant Inhaled Azacytidine With Platinum-Based Chemotherapy and Durvalumab (MEDI4736) - a Combined Epigenetic-Immunotherapy (AZA-AEGEAN) Regimen for Operable Early-Stage Non-Small Cell Lung Cancer (NSCLC)

    Status changed to Suspended · ClinicalTrials.gov · via pemetrexed

  2. Trial status changed2026-08-17

    Phase III Randomized Trial of Proton Beam Therapy (PBT) Versus Intensity Modulated Photon Radiotherapy (IMRT) for the Treatment of Esophageal Cancer

    Status changed to Active, not recruiting · ClinicalTrials.gov · via capecitabine

  3. Trial results posted2026-07-20

    A Phase 3, Randomized Study to Evaluate the Efficacy and Safety of Pembrolizumab (MK-3475) + Lenvatinib (E7080/MK-7902) + Chemotherapy Compared With Standard of Care as First-line Intervention in Participants With Metastatic Esophageal Carcinoma.

    Results posted · ClinicalTrials.gov · via Fluorouracil

  4. Trial status changed2026-07-20

    A Phase 3, Randomized Study to Evaluate the Efficacy and Safety of Pembrolizumab (MK-3475) + Lenvatinib (E7080/MK-7902) + Chemotherapy Compared With Standard of Care as First-line Intervention in Participants With Metastatic Esophageal Carcinoma.

    Status changed to Completed · ClinicalTrials.gov · via Fluorouracil

  5. Label change2026-07-01

    Label change: CAPECITABINE (ANDA210203)

    fda · regulatory · fda · via capecitabine

  6. Label change2026-07-01

    Label change: CAPECITABINE (ANDA211724)

    fda · regulatory · fda · via capecitabine

  7. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    fda · regulatory · fda · via capecitabine

  8. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    fda · regulatory · fda · via capecitabine

  9. New publication2025-05-30
    Encorafenib, Cetuximab, and mFOLFOX6 in <i>BRAF</i>-Mutated Colorectal Cancer.

    The New England journal of medicine · 2025 · 55 citations · Europe PMC · via Fluorouracil

  10. New publication2025-01-25
    Encorafenib, cetuximab and chemotherapy in BRAF-mutant colorectal cancer: a randomized phase 3 trial.

    Nature medicine · 2025 · 45 citations · Europe PMC · via Fluorouracil

  11. New publication2024-12-26
    MOUNTAINEER-03 phase III study design: first-line mFOLFOX6 + tucatinib + trastuzumab for HER2+ metastatic colorectal cancer.

    Future oncology (London, England) · 2025 · 8 citations · Europe PMC · via Fluorouracil

  12. New publication2024-09-12
    Datopotamab Deruxtecan Versus Chemotherapy in Previously Treated Inoperable/Metastatic Hormone Receptor-Positive Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer: Primary Results From TROPION-Breast01.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2025 · 113 citations · Europe PMC · via capecitabine

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.

Research activity

1 papers · to 2020

Papers linked directly to this protein. This is the protein's own literature — descriptor-derived papers are kept separate below.

Most cited

Recent

Europe PMC papers linked directly to this protein.