In humans, two forms of diacylglycerol lipase, DAGLα and DAGLβ, generate the endocannabinoid 2-arachidonoyl glycerol (2-AG; ) by attacking DAG at the sn-1 position. KT109 is a selective inhibitor of DAGLβ with an IC50 value of 42 nM. It demonstrates ~60-fold selectivity for DAGLβ over DAGLα, and negligible activity against other key enzymes involved in endocannabinoid signaling, including FAAH, MAGL, and ABHD11. KT109 has been shown to disrupt the lipid network involved in macrophage inflammatory responses, lowering 2-AG, as well as arachidonic acid and eicosanoids, in mouse peritoneal macrophages.