Thus, the association of MC5R with schizophrenia could theoretically represent a gene-environment interaction relevant to the outcome seen for Afro-Caribbean peoples migrating to the U.K. MC5R is a receptor for alpha-MSH which, as described above, is one of the light-responsive hormones elevated during long-day photoperiods and when light levels are more intense. Here, POMC is linked to schizophrenia.