{"entity":{"id":"kir2dl1","kind":"target","name":"KIR2DL1 (inhibitory KIR)","aka":["KIR","CD158a","p58.1","KIR2DL2","KIR2DL3","CD158b"],"tldr":"Inhibitory KIRs are the receptors NK cells use to recognise a person's own HLA-C and stand down. Lirilumab, an antibody that blocks three of them, reached phase 2 but was dropped for blood cancers.","summary":"KIR2DL1 (chromosome 19q13.42) is a receptor on NK cells for HLA-C alleles such as Cw4 and Cw6 that inhibits NK activity and so prevents lysis of the cell it recognises (UniProt P43626); KIR2DL3 does the same for HLA-Cw1, Cw3 and Cw7 (UniProt P43628). Lirilumab, an antibody against KIR2DL1, KIR2DL2 and KIR2DL3, was tested in phase 1/2 with nivolumab in solid tumours (NCT01714739); enrolment in myelodysplastic syndromes stopped after the sponsor decided not to pursue lirilumab for myeloid malignancies (NCT02599649), and a relapsed AML study ended because response rates did not reach the anticipated minimum of 30 percent (NCT02399917).","asOf":"2026-09-24","links":[{"label":"HGNC HGNC:6329","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6329"},{"label":"UniProt P43626","url":"https://www.uniprot.org/uniprotkb/P43626/entry"},{"label":"NCBI Gene 3802","url":"https://www.ncbi.nlm.nih.gov/gene/3802"},{"label":"ClinicalTrials.gov NCT02599649","url":"https://clinicaltrials.gov/study/NCT02599649"}],"tags":["checkpoint-map"],"related":["klrc1","nk-cell","nivolumab"],"cancers":["mds","aml"],"sections":[],"technologies":["checkpoint-inhibitor"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["cancer-immunity-cycle"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded: HGNC and UniProt carry no positivity rates."],"provenance":{"editedBy":"OnCo checkpoint map (HGNC REST, UniProt REST, ClinicalTrials.gov v2)","editedOn":"2026-09-24"},"symbol":"KIR2DL1","role":["immune-checkpoint"],"sources":[{"label":"HGNC HGNC:6329","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6329","note":"approved symbol, name, aliases and cross-references"},{"label":"UniProt P43626","url":"https://www.uniprot.org/uniprotkb/P43626/entry","note":"protein name, function and tissue specificity"}],"specificitySources":[],"hgnc":"HGNC:6329","ensembl":"ENSG00000125498","uniprot":"P43626","entrez":"3802","biology":"Immunoglobulin-like receptors with long cytoplasmic tails (2DL, 3DL) inhibit through ITIMs; short-tailed KIRs activate. This record stands for the inhibitory KIR2DL group the antibody binds.","whereFound":["NK cells (UniProt P43626)","Myelodysplastic syndromes and acute myeloid leukaemia trials of lirilumab (terminated)"],"targetClass":"checkpoint","prevalence":[]},"route":"/targets/kir2dl1/","neighbours":{"target":[{"id":"klrc1","kind":"target","name":"NKG2A (KLRC1)","route":"/targets/klrc1/"}],"term":[{"id":"checkpoint","kind":"term","name":"Checkpoint (two meanings)","route":"/terms/checkpoint/"},{"id":"nk-cell","kind":"term","name":"NK cell","route":"/terms/nk-cell/"}],"drug":[{"id":"nivolumab","kind":"drug","name":"Nivolumab","route":"/drugs/nivolumab/"}],"cancer":[{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"mds","kind":"cancer","name":"Myelodysplastic syndromes / neoplasms (MDS)","route":"/cancers/mds/"}],"technology":[{"id":"checkpoint-inhibitor","kind":"technology","name":"Immune checkpoint inhibitors","route":"/technologies/checkpoint-inhibitor/"}],"pathway":[{"id":"cancer-immunity-cycle","kind":"pathway","name":"The cancer-immunity cycle","route":"/pathways/cancer-immunity-cycle/"}]}}