Saffari et al (2013) studied the effect of the MTHFR C677T on high homocysteine levels and therefore coronary artery disease (CAD). Overall the correlation between C677T and CAD was not found to be significant, although homocystiene levels were found to be higher in the CAD study group. MTHFR C677T mutation, folate levels and smoking habits were the main predictors of high homocystiene levels, which all can relate to negative cardiovascular outcomes.