Fig. 9From: Antiestrogen- and tamoxifen-induced effects on calcium-activated chloride currents in epithelial cells carrying the ∆F508-CFTR point mutationSchematic model of the possible mechanisms of action of tamoxifen. Tamoxifen could be active on different targets. It appears to downregulate estrogen stimulation. On the other hand, tamoxifen interacts with P2Y2 purinergic receptors, releasing calcium from the internal stores via IP3 stimulation. However, tamoxifen could upregulate the chloride membrane current by acting directly on CaCCBack to article page