These results are in keeping with loss of NKG2A expression with increasing NK cell differentiation in HIV infection and contrast findings of a dominant effect of the -21M HLA-B dimorphism on increasing the differentiated subpopulation of the educated KIR-NKG2A+ NK cells in Caucasian HCMV seronegative donors (6). The gene discussed is HLA-B; the disease is HIV infectious disease.