ANO1-IN-4 (Compound 10bm) is a reversible inhibitor for calcium-activated chloride channel transmembrane protein 16A ( TMEM16A , also known as ANO1 ) with an IC 50 of 0.030 µM. ANO1-IN-4 exhibits good metabolic stability in rat liver microsomes. ANO1-IN-4 inhibits spontaneous contraction in mouse isolated ileum.