Kir3dl2, also known as CD158k, is a member of the killer cell immunoglobulin-like receptor (KIR) family. It is expressed as a disulfide-linked homodimer on natural killer (NK) cells, rare circulating T lymphocytes (mainly CD8+), and has been found in certain cancer cells. It binds to HLA-A3,-A11, free heavy chain form of HLA-B27 and CpG oligonucleotides, playing roles in NK cell development, licensing, maturation and cell activation [2].

In cancer research, Kir3dl2 has emerged as a potential therapeutic target. In acute adult T-cell leukemia (ATL), its expression is associated with the acute-type subtype, different from lymphoma-and chronic/smoldering-type ATL, and may be triggered by HTLV-1 infection [1]. In cutaneous T-cell lymphomas such as Sézary syndrome, CD30+ cutaneous lymphoma, and transformed mycosis fungoides, Kir3dl2 is aberrantly expressed, and monoclonal antibodies against it are being used in diagnosis, follow-up, and treatment [2]. In hepatocellular carcinoma, reduced infiltrating NK cells expressing Kir3dl2 in recurrent cases suggest its potential as a prognostic marker [3].

In conclusion, Kir3dl2 is involved in NK cell-related functions and has significance in multiple diseases, especially in certain lymphomas and hepatocellular carcinoma. The identification of its role in these diseases through various studies provides a basis for developing targeted therapies against these malignancies.