PRNP and nutritional disorder: Widespread expression of PrPC in the anterior segment, predominance of β-cleaved PrPC in the ciliary epithelium, and a phenotype of relative iron deficiency in PrP−/− mice supports active participation of PrPC in iron transport as reported for outer retina and other cell types (Asthana et al., 2017; Haldar et al., 2015; Tripathi et al., 2015).