Besides CB1, several cannabinoid-responsive TRPV channels (namely TRPV1, TRPV3 and TRPV4) were shown to be functionally expressed in human HFs, and to promote the onset of catagen phase [135,136,137,138], which, considering that all three channels are heat-sensitive [45,94,95,139], may be an evolutionary relic of warmth-induced shedding. This evidence concerns the gene CNR1 and Hand-foot syndrome.