RBP4 and atherosclerosis: Gene polymorphisms CHI3L1 (rs946263), CD36 (rs1761667), LEPR (rs1137100), RETN (rs1862513 and rs3745367), IL-18 (rs1834481), RBP-4 (rs7094671), and RARRES2 (rs17173608) have the great potential to associate with IR and atherosclerosis in T2DM patients with CAD, as having possible evidence based on data from previous studies and the disease pathogenesis.