CD158k (KIR3DL2) is a member of the highly polymorphic family of killer-cell immunoglobulin-like receptors (KIRs) and is expressed on NK cells and a small proportion of CD8+ T cells, as well as CD4+ T cells in CTCL.161–163 The anti-CD158k mAb IPH4102 has been found to be potent and safe in preclinical studies.164 A phase 1 study (NCT02593045) demonstrated efficacy and safety in CTCL,165 with the expansion study ongoing. The gene discussed is CD4; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.