APEX1 and osteosarcoma: TGF‐β signaling plays a core regulatory role in the EMT process, and we previously demonstrated that APE1 promotes TGF‐β transcription in osteosarcoma, a malignancy derived from mesenchymal tissue.9 To further confirm this regulatory relationship in NSCLC epithelial cancer, TGF‐β secretion from cancer cells was evaluated by ELISA.