AOPEP and in situ carcinoma: However, there are few reports about the correlation between Lpa, APO-A, and APO-B and the degree of cerebral artery stenosis Based on this, this study intends to retrospectively analyze the correlation between Lpa, APO-A, APO-B, and MCA stenosis in CIS patients, aiming to provide a new research direction for clinical prevention and treatment of CIS.