POU4F1 and Optic neuropathy: Since glaucoma is defined as an optic neuropathy due to degeneration of RGC axons (Calkins, 2012), we focused on RGC development by looking at transcriptional activation of pou4f1 (also known as brn3a) which is expressed early in post-mitotic RGC precursors and plays an important role in their development (Badea et al., 2009; Nguyen-Ba-Charvet and Rebsam, 2020).