CM398 is an orally active chemical compound that acts as a highly selective ligand for the sigma-2 receptor (K i =0.43 nM), demonstrating a significant ratio of selectivity between sigma-1 and sigma-2 receptors (1000-fold). Moreover, CM398 exhibits notable affinity towards dopamine (K i =32.90 nM) and serotonin transporters (K i =244.2 nM). In addition, CM398 has shown promising efficacy as an anti-inflammatory analgesic in a mouse model of inflammatory pain induced by formalin [1].