Interestingly, a study by Tikellis et al. indicated that, in diabetic rats, CCN2/CTGF was localized mainly to the ganglion cell layer, where its expression was nearly two-fold that of non-diabetic controls, suggesting that CCN2/CTGF plays a pivotal role in mediating diabetes-associated retinal neuronal pathology [137]. Here, CCN2 is linked to diabetes mellitus.