To investigate the relation of higher apolipoprotein B/apolipoprotein AI (apoB/AI) ratio with the risk of suffering intracranial atherosclerotic stenosis (ICAS) in both stroke and non-stroke population, we enrolled 1138 patients with acute ischemic stroke (359 with ICAS, 779 without ICAS) and 1072 non-stroke controls (239 with ICAS, 833 without ICAS) into the study. The gene discussed is APOB; the disease is familial isolated congenital asplenia.