Description: The monoclonal antibody 3D12 (HLA-E) recognizes human HLA-E, a member of the Human Leukocyte Antigen family. HLA-E is a MHC Class IB member, which has a specialized role in NK cell recognition. Binding of a restricted set of peptides derived from other Class I leader sequences to the HLA-E and B2M (beta2 microglobulin) complex leads to interaction with NKG2A on NK cells. This binding protects the HLA-G-expressing cell from NK cell killing. HLA-E expression is ubiquitous.