As shown in Fig. 2, there was a negative association between IgM levels and CAD severity among people younger than 70 years of age, with a BMI greater than 24 kg/m2, who had never smoked, had hypertension, did not have hyperlipidaemia or diabetes, had no history of stroke, and did not have a history of statin use. The gene discussed is CD40LG; the disease is diabetes mellitus.