Protein / target
Cytotoxic T-lymphocyte protein 4
Protein at a glance
Biological role
Receptor decoy
Strongest disease association
Hypothyroidism
Therapeutic position
Established drug target
Research activity
Actively researched
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
Inhibitory receptor acting as a major negative regulator of T-cell responses.
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Inhibitory receptor acting as a major negative regulator of T-cell responses (PubMed:11279501, PubMed:11279502, PubMed:16551244, PubMed:1714933, PubMed:18641304, PubMed:28484017). Acts as a decoy receptor: the affinity of CTLA4 for its natural B7 family ligands, CD80 and CD86, is considerably stronger than the affinity of their cognate stimulatory coreceptor CD28 (PubMed:11279501, PubMed:11279502, PubMed:16551244, PubMed:1714933, PubMed:28484017)
Subcellular location
Domains and Gene Ontology detail (19)Hide
Domains & features
Gene Ontology
- Cclathrin-coated endocytic vesicle
- Cexternal side of plasma membrane
- CGolgi apparatus
- Cperinuclear region of cytoplasm
- Cplasma membrane
- Cprotein complex involved in cell adhesion
- Freceptor decoy activity
- Padaptive immune response
- PB cell receptor signaling pathway
- PDNA damage response
- Pimmune response
- Pnegative regulation of B cell proliferation
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Immune signalling
- ·adaptive immune response
- ·B cell receptor signaling pathway
- ·immune response
- ·negative regulation of B cell proliferation
View underlying pathways (3)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Interaction neighbourhood
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.
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
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.
Broader indication categories (1)Hide
Broad umbrella indications (e.g. “Neoplasms”). Shown here because every medicine also appears under a more specific disease above — kept for completeness, de-emphasised for clarity.
Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
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.
Cytotoxic T-lymphocyte protein 4 inhibitor
Indicated for Carcinoma, Hepatocellular, Carcinoma, Non-Small-Cell Lung, Neoplasms
Cytotoxic T-lymphocyte protein 4 inhibitor
Indicated for Carcinoma, Non-Small-Cell Lung, Carcinoma, Renal Cell, Colorectal Neoplasms, Melanoma
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
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 CTLA4
Gene-level evidence surfaced through the gene CTLA4that 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.
View evidence synthesis (5)Hide
This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. 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.
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Drug development
6 compounds recorded · 2 approved · 4 in clinical development
View all recorded compounds (6)Hide
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 molecules — Emerging
Antibodies — Strong
View underlying tractability evidence (5)Hide
Raw Open Targets tractability assessment buckets, by modality.
Safety-related annotations
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
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)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 2 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.
- Label change
Label change: IPILIMUMAB (BLA125377)
- Indication expanded
Indication expansion: IPILIMUMAB (BLA125377)
- Indication expanded
Indication expansion: IPILIMUMAB (BLA125377)
- Indication expanded
Indication expansion: IPILIMUMAB (BLA125377)
- Indication expanded
Indication expansion: IPILIMUMAB (BLA125377)
- New publicationRandomized, open-label, phase 2 study of nivolumab plus ipilimumab or nivolumab monotherapy in patients with advanced or metastatic solid tumors of high tumor mutational burden.
- New publicationPlasma versus Tissue Tumor Mutational Burden as Biomarkers of Durvalumab plus Tremelimumab Response in Patients with Metastatic Colorectal Cancer in the CO.26 Trial.
- New publicationFinal Results From a Phase I Trial and Expansion Cohorts of Cabozantinib and Nivolumab Alone or With Ipilimumab for Advanced/Metastatic Genitourinary Tumors.
- New publicationNeoadjuvant Immunotherapy in Locally Advanced Mismatch Repair-Deficient Colon Cancer.
- New publicationSequential immunotherapy and targeted therapy for metastatic BRAF V600 mutated melanoma: 4-year survival and biomarkers evaluation from the phase II SECOMBIT trial.
- Regulatory approval
Approval: Imjudo (EMA)
- Safety communication
Drug Safety Update: Ipilimumab (Yervoy): reports of cytomegalovirus (CMV) gastrointestinal infection or reactivation
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
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.