While a limited number of studies have been unable to histopathologically detect abnormal tau accumulation in retinas of patients (Ho et al., 2014; Williams et al., 2017), the first evidence of disease-associated tau hyperphosphorylation in post-mortem retinas of confirmed AD cases was reported by Schön and colleagues in 2012 (Figures 4A,B; Schön et al., 2012). The gene discussed is MAPT; the disease is Alzheimer disease.