This might be explained by the fact that ANO6 needs a strong increase of intracellular Ca2+ (50–100 μM) to mediate chloride conductance, which may only occur under pathological conditions such as apoptosis but not in viable cells upon administration of UTP.20 Thus ANO1 and ANO6, although sharing structural similarities, clearly have distinct functional properties in the context of cyst formation. This evidence concerns the gene ANO1 and cyst.