COL4A2 and coronary artery disorder: These genes included Cdh13 and Lpl from Cluster 1; Nfia, Col4a1 and Serpinh1 from Cluster 2; Arhgef12, Col4a2, Scarb1 and Cst3 from Cluster 3; Pecam1 and Aldh2 from Cluster 4 (Figure 3C), providing plausible molecular basis for the inextricable causal link between age and coronary artery disease.