The HP-3G10 antibody is specific for human CD161, also known as NKR-P1A, a type II transmembrane lectin-like receptor and member of the killer cell lectin-like receptor (KLR) family. CD161 exists as a homodimer which is prominently expressed on natural killer (NK) and NKT cells, where it is proposed to regulate the function of both cell types. CD161 is also found on T cell subsets, including T regulatory cells (Tregs), memory/effector CD4+ T cells, and CD8+ T cells. Th17 cells have been demonstrated to co-express CD161, as surface IL-17A+ cells are contained within the CD161+ fraction of CD4 T cells, so that CD161 (in combination with CCR6) is often used as a marker for enrichment of Th17 cells.

The HP-3G10 antibody may be used for flow cytometric analysis of CD161 on NK and NKT cells, as well as on various T cell subsets. The antibody is also reported to be cross-reactive with Baboon, Chimpanzee and Rhesus CD161.