CNR1 and hepatocellular carcinoma: We did not measure tissue levels of ECs such as 2-AG and anandamide in this study, one possibility is that hepatic injury and disease conditions such as hepatocellular carcinoma in humans32 and liver cirrhosis in rats33 lead to increased amounts of intra-hepatic ECs that then were permissive to hepatocyte damage in the presence of a toxin such as Con A. CB1R is constitutively active in hCNR1+/+ mice.