All this permits recalling that exposing the taurine-TauT system to higher glucose concentrations “in vitro” is completely different from testing it in a clinical condition such as diabetes, which is characterized by a much longer exposure time to extracellular high glucose levels and moreover includes a more complex biochemical milieu done by amino acids, lipids, or oxidative stress-associated metabolites. This evidence concerns the gene SLC6A6 and diabetes mellitus.