We observed a significantly lower concentration of total serum IgM in the CAD patient group (0.63 ± 0.24 g/L) compared to young healthy volunteers (1.07 ± 0.40 g/L), young smokers (1.01 ± 0.43 g/L) and heavy smokers (1.07 ± 0.53 g/L) (Figure 6B). The gene discussed is CD40LG; the disease is coronary artery disorder.