Regarding the activating receptor CD94/NKG2C, whose expression has been found to be significantly increased in NK cells of normal individuals after CMV infection [164,165], a recent study has shown that CLL patients exhibit a reduced percentage of CD94/NKG2C+ NK cells compared with healthy donors, which is independent of CMV serostatus but is related to the exposure to leukemic cells, given its association with higher lymphocytosis [172]. This evidence concerns the gene KLRD1 and cytomegalovirus infection.