The type-II transmembrane glycoprotein CD94 covalently associates with C-type lectins of the NKG2 family to yield heterodimers important in NK cell recognition of class I MHC molecules. CD94/NKG2A complexes are also found on a subset of CD8+ T cells. Expression of CD94/NKG2 heterodimers may regulate cell survival and effector functions. There are two alternatively spliced variants of CD94 that differ by 31 amino acids encoded by exon 2.