SLC17A9 and glaucoma: For instance, VNUT helps regulate neuronal differentiation of neuroblastoma N2a cells (Menendez-Mendez et al., 2015) Moreover, during the development of glaucoma, there is a direct correlation between enhanced VNUT expression in the intern plexiform layers of the retina and an increase in extracellular ATP (Perez de Lara et al., 2015).