MCH has been found to couple to Gi/o and Gq protein pathways in cell culture models, although the selectivity for each varies among cellular context; in CHO cells [28] and in HEK293 cells [29] MCH causes activation of ERK via both G proteins, but in SK-MEL37 melanoma cells MCHR1 only couples to Gi/o [30]. This evidence concerns the gene PMCH and melanoma.