The 14B11 antibody reacts with a common epitope of Ly-49C/F/I/H family members also known as Ly-49 inhibitory receptors C, F, and I and activating receptor H. It does not react with other Ly-49 members (i.e., Ly-49A, B, D, and G). Ly-49 is a type-II transmembrane, disulfide-linked homodimer with C-type lectin extracellular domains that binds to MHC class I. Ly-49C/F/I/H is expressed on a subset of NK cells, NK-T cells and some CD8+ cells. Ly-49C/F/I, like other members of this family, inhibits NK cell activation through the recognition and interaction of certain MHC class I haplotypes on potential target cells. Ly-49C, Ly-49F, and Ly-49I contain an ITIM motif in their cytoplasmic tails, while Ly-49H lacks ITIM. Ly-49H is encoded by the Cmv1r gene, which promotes resistance to infection by mouse cytomegalovirus (CMV). BALB/c mice are reported to lack the Ly-49H and Ly-49I receptors. The 14B11 antibody, when bound to NK cells, is capable of inducing redirected cell lysis and blocking NK cell effector function.