TRPC6 and glaucoma: Moreover, in a randomization study, the concentration of TRPC6 in blood leukocytes of primary open-angle glaucoma (POAG) patients was twice as high as that in healthy people, and the expression level of TRPC6 was correlated with IOP and the cup-to-disk ratio, suggesting that the TRPC6 channel protein may be involved in the development of glaucoma and has the potential to become a biomarker for POAG (Chen et al., 2013).