Additionally, and interestingly, CD8+ T cells co-cultured with MHC-I-negative tumor cells and cognate antigen-loaded macrophages upregulated the inhibitory receptor NKG2A (Klrc1) (Fig. 5b), which binds to β2m-dependent Qa-1 (HLA-E in humans)50,51. This evidence concerns the gene HLA-E and neoplasm.