HLA-E and infection: Our study investigated the presence of circulating HLA-E-restricted CD8 T cells in a cohort of kidney transplant recipients (KTR, n = 121) during either an active HCMV infection (at primary infection or at reactivation) or at latency and in HCMV seropositive (HCMV+) healthy volunteers (HV, n = 25).