PPIF and hepatocellular carcinoma: To determine whether the mechanism identified in melanoma is applicable to other cancer types, we examined SK-Hep1 and PC3 cells, which originate from hepatocellular carcinoma and prostate cancer, respectively, and are known for their high metastatic properties.43,44 Under normoxic conditions, CypD knockdown resulted in increased levels of HIF1α, EMT markers, ROS production, and invasiveness in both cell lines (Supplementary Fig. 7a–c).