XP patients studied. A and B: Case 1 XP-A patient (A) at age 17y with numerous freckle-like pigmented lesions on sun exposed skin and (B) at 37y with marked cachexia and thinning of subcutaneous tissues of face and chest. She had more that 100 surgical procedures on her face for removal of skin lesions. C: Case 2 XP-D patient at age 40y. She had been well protected from sun exposure since early childhood and had only few pigmented lesions and skin cancers. D: Case 3 XP-C patient, at age 29y with multiple freckle-like pigmented lesion on sun exposed skin and cheilitis. The patient underwent many surgical procedures for removal of skin cancers on her face. E and F: Case 4 XP-C patient, at age 28y (E) with multiple pigmented lesions, telangiectasia, cheilitis and corneal clouding. Multiple surgical procedures were performed on her face for removal of skin cancers and at age 48y (F) following exenteration of both orbits for treatment of ocular squamous cell carcinomas.