FGF21 and type 2 diabetes mellitus: Given the pleiotropic effects of FGF21, especially the close relation to lipid and glucose metabolism, detecting circulating FGF21 was the reflection of poor lipid metabolism and glucose metabolism in T2DM patients, which may explain the potential link between FGF21 and CAD, because lipid disorder was a risky factor for CAD in T2DM (22).