TMEM16A, also known as DOG1, ORAOV2, TAOS2 or ANO1 (anoctamin 1), is a 986 amino acid multi-pass membrane protein that localizes to both the cell membrane and the cytoplasm and belongs to the anoctamin family. Expressed in a variety of tissues with highest expression in skeletal muscle and liver, TMEM16A functions as a calcium-activated chloride channel that is required for normal tracheal development. Human TMEM16A shares 90% sequence identity with its mouse counterpart, suggesting a conserved role between species. TMEM16A is present in breast, pancreatic, gastric, and uterine cancers, as well as in neck, ovarian and parathyroid tumors, suggesting a role for TMEM16A in carcinogenesis. Three isoforms of TMEM16A exist due to alternative splicing events.