MTOR and neoplasm: For example, FBXL1 promotes tumorigenesis by facilitating the degradation of a series of tumor-suppressor proteins, such as such as p21 and p27 (12); FBXO22 degrades nuclear PTEN to promote tumorigenesis (10); and FBXW7 plays a tumor-suppressive role by degrading various cancer-promoting proteins such as mTOR, cyclin E, MCL-1, N-Myc, and SOX9 (12, 14, 15).