UV reaching the DNA inside a skin cell Cross-section of sun-exposed skin. UVB rays stop in the epidermis and cause sunburn; UVA rays reach deeper, into the dermis. A zoomed-in skin cell shows UV damaging its DNA, and that damage building up over a career. SURFACE · BACK OF THE NECK PHASE 1 · HEALTHY CROSS-SECTION, NOT TO SCALE Damage UV kinks the DNA. Damage thatisn’t repaired stays and builds up. DNA The cell’s instructions, heldin its nucleus. Skin cell One cell from the base of theepidermis, zoomed in. Sunburn The part you feel. Underneath,UV is damaging DNA. UV light UVB burns the epidermis. UVAreaches deeper, into the dermis. LEGEND UVB UVA DNA damage

UV, DNA damage and skin cancer: R&R Lotion, Skin Cancer: Causes, Prevention and Treatment, white paper (2024). Illustration for education only.