For example, type 1 angiotensin-II receptor antagonist telmisartan used as an antihypertensive drug and H1 receptor antagonists, terfenadine used as antiallergic agent for many years, have been identified as potent CYP2J2 inhibitor at concentrations that are reached during clinical use and are well tolerated by patients,510,511 because terfenadone strongly inhibited CYP2J2-mediated metabolism process.512 However, the side effects of CYP inhibitors can not be ignored because of the important effects of CYP enzyme on drug metabolism and their double-edged sword on CVD and cancer treatment. This evidence concerns the gene CYP2J2 and cancer.