TGFB1 and coronary artery disorder: On the contrary, in 2006, Koch et al. did not find any significant genotype distributions difference of TGF-β1 gene -509C/T gene polymorphism between control and CAD patients and they concluded that the TGF-β1 gene -509C/T polymorphism was not associated with CAD in a Caucasian population (Koch et al., 2006).