PTPN1 and cancer: Subsequently, ROS inhibit the phosphatases PTEN (phosphatase and tensin homolog) and PTP1B (protein tyrosine phosphatase non-receptor type 1), negative regulators of the PI3K/Akt/mTOR and MAPK/ERK mitogenic signaling cascades, thereby driving the survival and proliferation of cancer cells [19,20,21].