KLRC2 and cytomegalovirus infection: Even though NKG2C+ and NKG2C- human NK cells might represent the counterparts of the recently described Ly49H+ and Ly49H- mouse NK cells, which acquire their adaptive functional superiority by either receptor- or cytokine-mediated stimulation, respectively69, it has remained difficult to demonstrate a protective function for the NK cell expansions during HCMV infection.