Clopidogrel pharmacokinetics and pharmacodynamics vary widely despite exclusion or control of polymorphisms (CYP2C19, ABCB1, PON1), noncompliance, diet, smoking, co-medications (including proton pump inhibitors), and pre-existent variability in platelet function - Frelinger, AL, 3rd; Bhatt, DL; Lee, RD (J Am Coll Cardiol, 2013)