Furthermore, the induction of HO-1 expression by CBD in microglial cells [41,42] and keratinocytes [43] as well as by CB2 agonists in Kupffer cells [44] and in myocardium [45,46] was reported, whereas the incubation of glioma cells with the CB2 agonist JWH-133 led to a reduced HO-1 gene expression [47]. Here, CNR2 is linked to central nervous system cancer.