B3GAT1 and viral hepatitis: Expansion of the NKG2C+CD57+ NK cell subset has also been reported in HCMV+ individuals with chronic hepatitis B and hepatitis C infections, although the proportions of these cells did not differ markedly from previous reports in HCMV-infected but hepatitis virus-uninfected donors, leading the investigators to conclude that HCMV, rather than viral hepatitis, is the underlying driver of NK cell differentiation (97).