CTCF and infection: To further explore the roles of the individual CTCF insulators in HSV-1 transcriptional control, we generated a recombinant virus with the CTRL2 insulator deleted from the 17Syn+ parent virus, a well-characterized parent strain of HSV-1 known to be a virulent and reactivating strain of HSV-1 in both mice and rabbit ocular models of infection.