To study the mechanism underlying circFOXP1 promoting the angiogenesis of osteosarcoma, we further explored the regulatory effect of circFOXP1 on CDKN2AIP, and found that both CDKN2AIP mRNA (Figure 3a) and protein (Figure 3b) expression decreased after inhibiting circFOXP1 expression in osteosarcoma. This evidence concerns the gene CDKN2AIP and osteosarcoma.