The function of ANXA13 (annexin A13, ENSG00000104537) is as follows. [Isoform A]: Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner (PubMed:27676605, PubMed:30610115). Half-maximal membrane binding requires about 60 uM calcium. Does not bind to membranes that lack phospholipids with an acidic headgroup (PubMed:27676605). . [Isoform B]: Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner, but requires higher calcium levels for membrane binding than isoform A. Half-maximal membrane binding requires about 320 uM calcium. .