Finally, due to the critical role ascribed to the endogenous inhibitor protein (IF1) of the mitochondrial F1F0-ATPase in the regulation of cancer cell energy metabolism [20,21,22,23,24], we assayed whether IF1 is involved in the control of ROS generation in osteosarcoma cells and whether ROS handling could distinguish normal from transformed cells. This evidence concerns the gene ATP5IF1 and osteosarcoma.