SkinKeratinocytesUltraviolet RaysMelanocytesFibroblastsEpidermisSkin NeoplasmsCells, CulturedSkin AgingDose-Response Relationship, RadiationSkin Physiological PhenomenaSkin, ArtificialDermisSkin DiseasesSkin PigmentationSkin AbsorptionSunlightMice, HairlessCysteamineMelaninsWound HealingSkin TestsAdministration, TopicalPyrimidine DimersDNA DamageErythemaOxidative StressCell LinePhotosensitizing AgentsMelanomaKeratinsCell Line, Transformed