Calcium activated Chloride Channels (CaCCs) are anion-selective channels that are activated by increases in cytosolic Ca²⁺. They have been implicated in a variety of cellular functions such as fertilization of the oocyte, transepithelial fluid transport, repolarization and action potential duration in cardiac myocytes, olfactory transduction, and regulation of smooth muscle tone. Within the airways, they contribute to epithelial fluid secretion[1]. TMEM16A (alternative name, anoctamin-1, ANO1) was identified as a CaCC, as its heterologous expression in oocytes and mammalian cells produced outwardly rectifying, Ca2+-sensitive Cl− currents. It is expressed in epithelial cells in airways, salivary gland, intestine, and other tissues, as well as in arterial smooth muscle, intestinal pacemaker cells, sensory neurons, and various tumors. Evidence was found for involvement of ANO1 in  chloride secretion in salivary gland and airway epithelia, intestinal and vascular smooth muscle contraction, nociception, and bile formation[2].