Energy restriction, fasting state, and physical activity, can be associated with an elevated gene expression of OCTN2 in some tissues such as the liver and kidney; which in turn could lead to metabolism improvement.14,58 Furthermore, L-carnitine reportedly enhances the efficacy of fatty acid metabolism by increasing non-oxidative glucose disposal.59 Accordingly, L-carnitine supplementation can, conceivably, ameliorate the status of glycemic and lipid profile in patients with type 2 diabetes and metabolic syndrome. Here, SLC22A5 is linked to metabolic syndrome.