NKG2-A/NKG2-B Type II Integral Membrane Protein contains 1 C-type lectin domain and belongs to the killer cell lectin-like receptor family. The killer cell lectin-like receptor family is a group of transmembrane proteins preferentially expressed in NK cells. Members of this proteins is characterized by the type II membrane orientation and the presence of a C-type lectin domain. NKG2 is expressed only in NK-cells, but not in T-cells or B-cells. It has been shown that NKG2 represents a family of related cDNA clones, designated NKG2A, NKG2B, NKG2C, and NKG2D, which encode type 2 integral membrane proteins (extracellular C-terminus) containing a C-type lectin domain. NKG2 plays a role as a receptor for the recognition of MHC class I HLA-E molecules by NK cells and some cytotoxic T-cells. NKG2A and NKG2B have been given the designation CD159a in the nomenclature of CD antigens.