CYP1A2 and diabetes mellitus: Growing evidence has demonstrated that diabetes increases the expression of some CYP450s (such as CYP2A1, CYP1A2, CYP2B1/2, CYP2C6, CYP2C7, CYP3A1/2 and CYP2E1) in rats [9,11,12,26,27,28,29,30], although opposite reports have also been shown [31,32].