KLRA3 (also known as Ly49C) is a member of the LY49 family of receptors in Natural Killer (NK) cells that bind to major histocompatibility complex (MHC) class 1. These proteins are classified as either activating or inhibitory receptors based on whether they possess an immunoreceptor tyrosine-based inhibitory motif (ITIM) in their cytoplasmic region (for inhibitory receptors), or an immunoreceptor tyrosine-based activation motif (ITAM) that transmits activating signals resulting in phosphorylation of several substrates. KLRA3 is thought to be an inhibitory receptor, recognizing peptide -receptive H-2Kb.