PPEE inhibits VM formation in osteosarcoma both in vitro and in vivo by downregulating the expression of FAK and migration-inducing gene 7 (MIG-7), suppressing the activities of MMP2 and MMP9, and reducing the number of CD31-/PAS+ channels in vivo (Yao et al., 2017). The gene discussed is MMP2; the disease is osteosarcoma.