In this present single-center, prospective study, by analyzing the circulating lipid profile and the major adverse cardiovascular events (MACEs) among ACS patients with or without DM, we aimed to evaluate the relationship between the HDL-C/apoA-I ratio and the severity of coronary artery stenosis and also to explore the short-term prognostic value of the HDL-C/apoA-I ratio in ACS patients. The gene discussed is APOA1; the disease is coronary stenosis.