SLC22A6 and diabetic kidney disease: As mentioned earlier, renal Oat1 and 3 were influenced by certain pathological status and strongly correlated with the progression of diabetic kidney diseases [16] and para-aminohippurate (PAH) is a prototypical substrate for rOat1 and 3 transporters that are mainly localized on the basolateral membrane of renal proximal tubules [8, 9, 11].