However, some glaucoma patients continue to lose vision despite having well controlled IOPs.2 This has led to a search for alternative strategies to promote RGC preservation.3 Experimental glaucoma models and whole-retinal mounts have proven a useful ex vivo tool for the assessment of potential new treatments using well-established protocols for labelling RGCs, including using nuclear-restricted transcription factor brain-specific homeobox/POU domain protein 3A (Brn-3A). Here, POU4F1 is linked to glaucoma.