{"entity":{"id":"cd25","kind":"target","name":"CD25 (IL-2 receptor alpha)","aka":[],"tldr":"CD25 is the part of the interleukin-2 receptor found on activated T cells and on some lymphoma cells; denileukin diftitox uses it as a doorway to deliver a toxin.","summary":"CD25, the alpha chain of the high-affinity interleukin-2 receptor (IL2RA), is expressed on activated T cells, regulatory T cells and the malignant cells of cutaneous T-cell lymphoma, adult T-cell leukaemia/lymphoma and some Hodgkin and B-cell lymphomas. Denileukin diftitox, a fusion of IL-2 with diphtheria toxin fragments, binds CD25-expressing cells and kills them by blocking protein synthesis; it was approved in 1999, withdrawn in 2014 for manufacturing reasons and reapproved as Lymphir in 2024 for relapsed or refractory stage I to III CTCL. Anti-CD25 antibodies (basiliximab, daclizumab) are used in transplantation and were studied in leukaemia and for regulatory T-cell depletion.","asOf":"2026-09-10","wikipedia":"https://en.wikipedia.org/wiki/IL2RA","links":[{"label":"NCBI Gene IL2RA","url":"https://www.ncbi.nlm.nih.gov/gene/3559"}],"tags":["surface-antigen"],"related":[],"cancers":["hodgkin-lymphoma","peripheral-t-cell-lymphoma"],"sections":[],"technologies":[],"targets":[],"drugs":["denileukin-diftitox","tak-928"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":["shimon-sakaguchi"],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"IL2RA","role":[],"sources":[],"specificity":"immune-microenvironment","distribution":"one-type","specificityNote":"Immune or microenvironment target: its medicines act on immune, stromal or bone cells rather than on the tumour cell (drug mechanisms in the corpus). HPA IL2RA: RNA tissue enhanced (adipose tissue 18 nTPM, lymphoid tissue 17 nTPM, urinary bladder 10 nTPM); blood lineage group enriched (granulocytes 193 nTPM, T-cells 271 nTPM); high antibody staining in 1 normal tissue. Distribution: 1 cancer family in the corpus carries a prevalence row, label threshold or catalogue link for it (Lymphoma); Open Targets associates it with 2 specific cancer types at or above 0.5 (primary cutaneous T-cell non-Hodgkin lymphoma, renal cell carcinoma); the corpus evidence decides and the Open Targets list is quoted for comparison. (Rule 1 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas IL2RA tissue","url":"https://www.proteinatlas.org/ENSG00000134460-IL2RA/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"UniProt P01589","url":"https://www.uniprot.org/uniprotkb/P01589/entry","note":"involvement in disease"},{"label":"Open Targets ENSG00000134460 associations","url":"https://platform.opentargets.org/target/ENSG00000134460/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:6008","ensembl":"ENSG00000134460","uniprot":"P01589","entrez":"3559","firstDescribed":1984,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Nikaido et al, Nature, 1984, \"Molecular cloning of cDNA encoding human interleukin-2 receptor\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/6090949/","biology":"CD25 confers high-affinity IL-2 binding; its density on regulatory T cells makes it a candidate for depleting immunosuppressive cells in the tumour microenvironment.","whereFound":["Cutaneous T-cell lymphoma (about half of cases express CD25)","Adult T-cell leukaemia/lymphoma","Hodgkin lymphoma (Reed-Sternberg cells)"],"targetClass":"surface-antigen","prevalence":[{"cancerId":"hodgkin-lymphoma","pct":58,"measure":"IHC (anti-Tac), IL-2 receptor in >10% of cells, 12 Hodgkin's disease cases","source":"https://pubmed.ncbi.nlm.nih.gov/3103454/","note":"Strauchen and Breakstone 1987 (Am J Pathol), 166-case series; positivity includes Reed-Sternberg cells"},{"cancerId":"peripheral-t-cell-lymphoma","pct":86,"measure":"IHC (anti-Tac), IL-2 receptor in >10% of cells, 13 peripheral T-cell lymphomas","source":"https://pubmed.ncbi.nlm.nih.gov/3103454/","note":"Strauchen and Breakstone 1987; in cutaneous T-cell lymphoma Jones 2004 found strong CD25 in 13 of 17 skin biopsies with lower expression in paired lymph nodes (doi:10.1158/1078-0432.CCR-0721-03)"}]},"route":"/targets/cd25/","neighbours":{"cancer":[{"id":"hodgkin-lymphoma","kind":"cancer","name":"Hodgkin lymphoma","route":"/cancers/hodgkin-lymphoma/"},{"id":"peripheral-t-cell-lymphoma","kind":"cancer","name":"Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma)","route":"/cancers/peripheral-t-cell-lymphoma/"}],"drug":[{"id":"denileukin-diftitox","kind":"drug","name":"Denileukin diftitox","route":"/drugs/denileukin-diftitox/"},{"id":"tak-928","kind":"drug","name":"TAK-928","route":"/drugs/tak-928/"}],"person":[{"id":"shimon-sakaguchi","kind":"person","name":"Shimon Sakaguchi","route":"/people/shimon-sakaguchi/"}]}}