Interactions of HLA-E with NKG2A on T cells and NK cells was found to restrain cytotoxic anti-tumor effector functions [19,20], and a humanized monoclonal antibody interfering with this interaction can act as checkpoint inhibitor to rescue T cell functions against tumors, in a synergistic manner with blockade of the established PD-1 checkpoint [18]. This evidence concerns the gene KLRC1 and neoplasm.