PIEZO1 and Schnyder corneal dystrophy: The mechanosensitive Piezo1 channel was suggested previously as a molecular candidate for the Psickle current, based on observations that Piezo1 is expressed in RBCs, activated by membrane deformation (Cox et al., 2016), permeable to mono- and divalent cations, affected by inherited mutations linked to erythrocyte hydration disorders (Gallagher 2017; Lew and Tiffert 2017), and sensitive to block by a tarantula spider toxin which appeared to partially inhibit Psickle monovalent cation fluxes in deoxygenated conditions, as measured by whole cell patch clamp in SCD cells (Ma et al., 2012).