MC1R and Alzheimer disease: MC1R is predominant in the skin, where, aside from melanogenesis, MC1R also partakes in immune response, DNA repair and cell differentiation and proliferation via both pigment-dependent and -independent pathways and is also expressed in the brain, offering associations between certain pigmentary and neuronal health phenomena [101], such as the effects of α-MSH via the neuronal MC1R counterpart in ischemic stroke [102], traumatic brain and spinal cord injury [103,104], Alzheimer’s disease [105], Parkinson’s disease [106] and neuroinflammatory diseases as a neuroprotective agent.