Moreover, the DBA/2J mouse strain is a very well known model of secondary glaucoma to study neurodegeneration [72] displaying mutations of the genes encoding for the following two proteins: tyrosinase-related protein (TYRP1) and glycosylated transmembrane protein (GPNMB), leading to ocular hypertension for blockade of aqueous outflow by 9 months of age and consequent axonal damage of the optic nerve head [73]. Here, GPNMB is linked to ocular hypertension.