Genetic polymorphisms of genes that encode subunits of TFH are known to be associated with increased cancer susceptibility in many tissues, e.g.; skin tissue, breast tissue and lung tissue. Mutations in the subunits (such as XPD and XPB) can lead to a variety of diseases, including xeroderma pigmentosum (XP) or XP combined with Cockayne syndrome. In addition to genetic variations, virus-encoded proteins also target TFH.