Quantification of immunocytochemistry data from the left main coronary arteries of the entire patient cohort showed that while 84% of SMCs in patients with no/mild CAD demonstrated expression of p‐Smad2 in the media of their coronary arteries, this was reduced to 21% in patients with moderate CAD and 6% in patients with severe CAD (Fig 5D). This evidence concerns the gene SMAD2 and coronary artery disorder.