H2AX and viral infectious disease: Since it has been reported that phosphorylation of H2AX extends along megabase-long domains in chromatin with both sides of the damaged DSBs, which is a marker of DNA damage [20], higher levels of γH2AX protein in UV-treated cells following virus infection (Figure 7) may indicate an exacerbation of DNA damage, which confirmed the previous report that BoHV-1 productive infection induces DNA damage [10,13].