These pathways require XPA–G, CSA-B, TTDA, and UV-stimulated scaffold protein A (UVSSA) [16], whose deficiencies are associated with several human autosomal recessive genetic diseases, such as xeroderma pigmentosum (XP), Cockayne syndrome (CS), trichothiodystrophy (TTD), and UV sensitive syndrome (UVSS), respectively [16]. The gene discussed is UVSSA; the disease is Cowden syndrome 1.