Increase of CD56dim/CD16bright/NKG2C+ NK cells has also been found in patients with other viral infections, such as hepatitis C virus (HCV), hepatitis B virus (HBV) [64, 65], EBV (Epstein Barr Virus) [66], or HIV-1 [67], but only in people previously infected with HCMV as well, suggesting that expansion of the CD94/NKG2C+ NK cell subset is CMV specific rather than a generalized response after virus infection. This evidence concerns the gene KLRC2 and viral infectious disease.