MC1R and cancer: Many of the reported molecules involved in skin inflammation and cancer, such as C–C chemokine receptor type4 (CCR4), C–C chemokine receptor type10 (CCR10), involved in skin lymphocyte recruitment [19], G-protein-coupled estrogen receptor 1 (GPER1) [20], and melanocortin 1 receptor (MC1R), involved in melanocyte proliferation, pigmentary variation, sun sensitivity, and susceptibility to skin cancers [21,22], are G-coupled protein receptors (GPCRs).