Protein / target

Thymidylate synthase

TYMSP04818Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
9
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

MRNA regulatory element binding translation repressor activity

Strongest disease association

dyskeratosis congenita, digenic

Genetic evidence · score 0.82

Therapeutic maturity

Clinically validated target

9 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

9 approved · 2 in clinical development

30 linked trials

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

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.

Transcriptional regulationReactome
View supporting evidence

Transcriptional regulation

  • ·G1/S-Specific Transcription
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.

Drugs targeting this protein

3

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

Fluorouracil
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Appears in clinical studies involving adenocarcinoma, keratosis, basal cell carcinoma, head and neck cancer

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

pemetrexed
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Appears in clinical studies involving malignant pleural mesothelioma, mesothelioma, non-small cell lung carcinoma, neoplasm

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

capecitabine
Narrow target profileApprovedInhibitor

Thymidylate synthase inhibitor

Appears in clinical studies involving breast cancer, breast carcinoma, colonic neoplasm, colorectal cancer

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

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

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

dyskeratosis congenita, digenic0.82

Genetic · overall 0.66

dyskeratosis congenita0.78

Genetic · overall 0.60

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

non-small cell lung carcinoma0.99

Clinical · overall 0.63

breast cancer0.97

Clinical · overall 0.62

colorectal cancer0.97

Clinical · overall 0.61

mesothelioma0.96

Clinical · overall 0.59

colonic neoplasm0.95

Clinical · overall 0.60

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

neoplasm0.60

Literature

breast carcinoma0.60

Clinical

gastric neoplasm0.58

Clinical

Show all associations
dyskeratosis congenita, digenic0.66
non-small cell lung carcinoma0.63
breast cancer0.62
colorectal cancer0.61
colonic neoplasm0.60
neoplasm0.60
dyskeratosis congenita0.60
breast carcinoma0.60
mesothelioma0.59
gastric neoplasm0.58

Open Targets ranks 647 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 11 total

OSI-7904Phase 2

gastric adenocarcinoma · gastroesophageal junction adenocarcinoma · head and neck squamous cell carcinoma

CAPECITABINEApproval

breast cancer · breast carcinoma · colonic neoplasm

PEMETREXED DISODIUMApproval

non-small cell lung carcinoma · non-small cell lung carcinoma · malignant pleural mesothelioma

RALTITREXEDApproval

rectum adenocarcinoma · neoplasm · colorectal cancer

NOLATREXEDPhase 3

hepatocellular carcinoma

DOXIFLURIDINEApproval

gastric adenocarcinoma · gastric cancer

TEGAFURApproval

gastric cancer · head and neck cancer · non-small cell lung carcinoma

PEMETREXEDApproval

malignant pleural mesothelioma · mesothelioma · non-small cell lung carcinoma

FLOXURIDINEApproval

colorectal cancer · neoplasm · malignant colon neoplasm

FLUOROURACILApproval

adenocarcinoma · keratosis · basal cell carcinoma

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · High-Quality PocketSM · Druggable FamilyPR · UniProt UbiquitinationPR · Database UbiquitinationPR · Small Molecule Binder

Safety liabilities

discontinuation of therapy due to severe toxicityastheniadrug toxicitynausea and vomitingside effectsdiarrhea

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.

Show remaining trials (24)

ClinicalTrials.gov via the drug-target graph.

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.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

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

non-small cell lung carcinomaWell supported
0.79
agreement 0.650.92
Clinical80%Literature16%RNA expression4%

Open Targets aggregate 0.63 · 3 independent evidence families

breast cancerWell supported
0.77
agreement 0.610.92
Clinical85%Literature15%

Open Targets aggregate 0.62 · 2 independent evidence families

colorectal cancerWell 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 underlying per-type scores are shown above so the calculation can be checked.

What's happening now

60

Recent activity around this target, drawn from one canonical event stream. Every item is reached through 3 drugs that target this protein, so each event is news about that drug rather than about the protein directly.

  1. 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

  2. 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

  3. Label change2026-07-01

    Label change: CAPECITABINE (ANDA211724)

    fda · regulatory · fda · via capecitabine

  4. Label change2026-07-01

    Label change: CAPECITABINE (ANDA210203)

    fda · regulatory · fda · via capecitabine

  5. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    fda · regulatory · fda · via capecitabine

  6. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    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. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    fda · regulatory · fda · via capecitabine

  10. Label change2026-06-09

    Label change: CAPECITABINE (ANDA202593)

    fda · regulatory · fda · via capecitabine

  11. 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

  12. 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

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.