Is M c1r an important regulator of non‐pigmentary responses to UV radiation?

MC 1 R is recognized for its role in the regulation of melanin pigmentation. In addition, many investigators believe that it also plays a crucial role in immunomodulation (immunosuppression) and in melanogenesis‐independent protective responses against ultraviolet radiation ( UVR ). Surprisingly, W olnicka‐ G lubisz et al. have shown that loss of function in the MC 1R has no effect on inflammatory responses and immunosuppression induced by UVR in C 57 BL /6 mice as well as on the degree of UVA ‐induced DNA damage in the epidermis and dermis. These findings, by challenging the existing dogmas on the precise role of MC 1 R in non‐pigmentary responses to the UVR , mandate further research to either validate the presented data or to define to which degree these phenomena are restricted to the C 57 BL /6 mouse model or are applicable to other species including humans. The alternative target for immunomodulation is represented by MC 3 R . However, cutaneous expression of MC 3 R remains to be demonstrated.