For example, the heparan sulfate proteoglycan HSPG2 and the collagens COL4A1/2 serve as atheroprotective factors in cardiovascular tissue and repeatedly appeared as CAD risk loci in human genome-wide association studies.70,71 Thus, while not an aim of our study, one testable hypothesis is that these three circRNAs are not only biomarkers but might also be more intimately involved in CAD pathomechanisms. The gene discussed is COL4A1; the disease is coronary artery disorder.