PIGF and liver cancer: Qiu Jun-Jun et al. showed that the significant increase in MALAT1 in metastatic epithelial ovarian cancer cells promotes angiogenesis by activating the expression of VEGF, PIGF, and other factors [35], while Teng Fei et al. showed that the decrease in miR-424 in liver cancer cells promotes angiogenesis by increasing the expression of another protein, E2F7 [36].