In addition to RBCs, AQP1 channels are expressed in endothelial and epithelial membranes of many cells (Ma et al., 1998; Agre 2004; Maeda et al., 2009) including vascular endothelium, which is a key player in SCD vaso-occlusion events. The gene discussed is AQP1; the disease is Schnyder corneal dystrophy.