FOXP1 and atherosclerosis: To elucidate the impact of FOXP1 on vascular endothelial senescence and atherosclerosis in vivo, ApoE knock-out (KO) mice were injected with recombinant adeno-associated virus 9 (AAV9) carrying FOXP1 under the control of an endothelial-specific promoter ICAM2 (ICAM2-AAV9-FOXP1) (Figure 4A).