XPC and xeroderma pigmentosum: The investigation of the top-ranked genes of the “nucleotide excision repair” pathway yielded relevant biological evidence: XPC and DDB1 are involved in Xedoderma pigmentosum (XP), which is a pigmentary skin disorder characterized by solar hypersensitivity of the skin with dermal atrophy and high predisposition for developing cutaneous melanoma and squamous cell carcinoma of the skin (Li et al., 1993; Puumalainen et al., 2016).