POLK and infection: Several genes related to DNA metabolism are up-regulated during early timepoints of infection (3 h and 6 h post-infection), such as the DNA polymerases POLK and POLB, DNA helicase RECQL, and DNA glycosylase SMUG1, that are involved in various types of DNA repair, including mismatch repair, base excision repair, and direct repair (Costales et al., 2009).