FDX1 and squamous cell carcinoma: The protein of FDX1 was mainly localized to the mitochondria and was enhanced in cell lines of A-431 (human epidermoid carcinoma cells), U-2 OS (human osteosarcoma cells), U-251 MG (human glioma cells), and particularly in CACO-2 (human colorectal adenocarcinoma cells) (Supplementary Figures S2A–D).