Influence of pigmentation on skin cancer risk. Fair-skinned individuals with low levels of melanin in the epidermis display a UV sensitive phenotype, tending to burn rather than tan, after UV exposure. Recent data suggest that mutations that contribute to fair complexion and tanning impairment, specifically signaling defects in the melanocortin 1 receptor (MC1R), may also be associated with less efficient DNA repair in melanocytes. MC1R-defective individuals not only suffer higher realized doses of UV radiation because their skin is less able to block UV photons, but they may also accumulate more mutations from UV exposure because of defective DNA repair.