In summary, the relative accumulation of clonally expanded NKG2C+ NK cells lacking NKR‐P1A receptor expression during CMV infection correlates with reduced activation and proliferation of NKR‐P1A+ NK cells, resulting in under‐representation of NKR‐P1A+ NK cells in the adaptive NK cell compartment. Here, KLRB1 is linked to cytomegalovirus infection.