Palmitoyl serinol is a derivative of 2-palmitoyl glycerol (2-PG), an endogenous fatty acid ester that potentiates the signaling and in vivo activity induced by the endocannabinoid 2-arachidonoyl glycerol (2-AG).^1,2,3 It is a metabolite of human commensal bacteria and an agonist of GPR119, increasing cAMP levels in HEK293 cells expressing GPR119 (EC50 = 9 µM).⁴ Palmitoyl serinol (25 µM) reduces IL-4-induced decreases in the levels of long-chain fatty acid-containing ceramides in IL-4-stimulated HaCaT keratinocytes, an effect that can be blocked by the cannabinoid receptor 1 (CB1) antagonist AM-251.5 It also binds to PKCζ and induces apoptosis in F-11 neuroblastoma cells, an effect that can be blocked by the PKCζ inhibitor Gö 6983 .⁶