TGFBR2 and Optic neuropathy: To quantify the impact of Tgfbr2 reduction on the inner retina, we measured the thickness of the GCC, which is the sum of thicknesses of the retinal NFL, retinal ganglion cell layer, and inner plexiform layer, which are potentially involved in glaucomatous damage and have been used as a biomarker to monitor optic neuropathy in mouse models and in humans.48