CNR1 and Hand-foot syndrome: Of great importance, prototypic eCBs (i.e., AEA and 2-AG) were shown to be produced in human HFs, among which 30 μM AEA (but not 2-AG) was proven to inhibit hair growth by inducing premature catagen entry in a CB1-dependent manner, but, somewhat surprisingly, it did not influence the pigmentation of HFs.