Mutations in TFIIH subunits, including the XPB helicase, are associated with the inherited genetic disease Xeroderma Pigmentosum (XP), where failure of DNA repair and accelerated DNA damage drive carcinogenesis, especially in the skin to cause melanomas, squamous cell carcinomas, and basal cell carcinomas [145,146]. The gene discussed is ERCC3; the disease is squamous cell carcinoma.