We attempted to examine the roles of epigenetic agents targeting histone modifiers and chromatin remodelers, including Jumonji domain 2 containing histone demethylase (JMJD2), lysine methyltransferase 5B, enhancer of zeste 2 polycomb repressive complex 2 subunit, DNA topoisomerase, DNA methyltransferases and BRD4 in viral infection (Fig 1A). The gene discussed is KDM4A; the disease is viral infectious disease.