MC1R and cancer: Persons with a phenotype mediated by one of these MC1R genetic variants are at greater risk of UV-induced skin cancers, because pheomelanin not only provides less effective protection against UV than does eumelanin, but it also generates more mutagenic free radicals in response to UV.[16] Apart from their role in determining a cancer-prone pigmentory phenotype, it has been demonstrated that certain MC1R variants play a direct role in the pathogenesis of cutaneous squamous cell carcinoma, cutaneous basal cell carcinoma and cutaneous melanoma [5, 13, 16].