This study demonstrated that overexpression of C1QL1 elevated the plasma HDL-C, but it was not related to aortic atherosclerosis present in ApoE KO mice, nor were significant differences found in plasma TC, TG, LDL-C, and glucose, which, in turn, indicated that the increase in the HDL-C level did not improve the formation of atherosclerotic plaque induced by C1QL1. Here, APOE is linked to aortic atherosclerosis.