MAPT and neurodegenerative disease: P38 mitogen-activated protein kinases (p38 MAPK) are a class of MAPK responsive to stress signaling, and phosphorylation of these has a strong association with neurodegenerative disease.22, 23 In the retina, elevated phosphorylated p38 MAPK (p-p38 MAPK) and downstream targets, Hsp27 and Tau, are associated with RGC injury and loss of anterograde transport in rodent models of OHT.10, 24 With this in mind, we did immunostaining to localize phosphorylated p38 MAPK, Hsp27 and Tau on retinas from anterograde transport experiments.