Enhanced NKG2A signaling may also be present in individuals with an HLA-B-21 genotype resulting in more HLA-E-presentable peptides and elevated HLA-E expression.16 31 However, a recent study suggests that these HLA-B-21 peptides outcompete other peptides and bind to HLA-E to generate an NKG2A antagonist/partial agonist.33 We did not observe any impact on outcome based on the NKG2A SNP in AML patients with HLA-B-21 M/x. Here, HLA-E is linked to acute myeloid leukemia.