Finally, if our analyses excluded a significant relation between TauT mRNA gene expression and diabetes duration (r = −0.26; P = 0.06), further studies are needed to confirm the hypothesis that a way by which prolonged duration of hyperglycemia may induce the appearance of retinopathy can be also due to the progressive fading in upregulation of TauT gene expression. The gene discussed is SLC6A6; the disease is diabetes mellitus.