PSB-KK1445 is an agonist of GPR18.1 It is selective for GPR18 over GPR55 in β-arrestin recruitment assays using CHO-K1 cells expressing the human receptors (EC50s = 0.0454 and >10 uM, respectively) and does not bind to cannabinoid 1 (CB1) or CB2 receptors (Kis = >10 uM for both).
References:
[1]. Mahardhika, A.B., Zauski, M., Schoeder, C.T., et al.Potent, selective agonists for the cannabinoid-like orphan G protein-coupled receptor GPR18: A promising drug target for cancer and immunityJ. Med. Chem.67(12)9896-9926(2024).