KLRC2 and cytomegalovirus infection: Interestingly, KLRC4, one of genes encoding NKG2C, which is induced on circulating NK cells by CMV infection and reactivation both after HSCT (20–22, 27) and SOT, including LTx (68–70), was found to be over-expressed in tolerant LTx patients in two different cohorts (59, 71).