tion motif (ARAM). KIRs and other inhibitory receptors also possess a common cytoplasmic sequence (I/VxYxxL/V) known as an ITIM (immunoreceptor tyrosine-based inhibitory motif). The human inhibitory human killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), also referred to as 2DL4 or CD158d, triggers potent IFN-γ responses but weak cytotoxicity in resting NK cells because of the low stoichiometric association with γ
