Thought to form a receptor-activated non-selective calcium permeant cation Channel. Probably is operated by a phosphatidylinositol second messenger system activated by receptor tyrosine kinases or G-protein coupled receptors. Has also been shown to be calcium-selective (By similarity). May also be activated by intracellular calcium store depletion. Mediates calcium-dependent phosphatidylserine externalization and apoptosis in neurons via its association with PLSCR1 (By similarity).