Retinal immunohistochemistry showed pAMPKThr172 increase in ocular hypertension in several cell types, consistent with the highly conserved nature of AMPK as an energy sensor and metabolic regulator [40], including RGC visualized with the cell-specific marker Brn3a (brain-specific homeobox/POU domain protein 3A) [41] (Fig. 2E-H). Here, POU4F1 is linked to ocular hypertension.