We also adopted Proximity Ligation Assays (PLA) and immunofluorescence stainings (IF), which further showed that USP9X and HIF-2α were largely colocalized in the nuclei and cytoplasm across different ovarian cancer cells with or without TGF-β1 treatment, and the interaction between USP9X and HIF-2α was strengthened by TGF-β1 treatment (Fig. 3F, Supplementary Fig. S3E and Movies S1–10). This evidence concerns the gene EPAS1 and ovarian carcinoma.