Therefore, we conducted a mendelian randomized study to explore the causal relationship between PD-1/PD-L1 and five specific types of CHD (chronic ischemic heart disease, acute myocardial infarction, angina pectoris, coronary atherosclerosis, and unstable angina pectoris), complemented by GSEA for further validation. The gene discussed is PDCD1; the disease is intermediate coronary syndrome.