MTOR and neoplasm: FBXW2 reduction results in SKP2 accumulation to promote targeted ubiquitylation and degradation of a number of tumour suppressors and apoptosis-inducing substrates such as p21, p27, p130 and FOXO1, leading to the activation of the CDKs, E2F and mTOR pathway73 to promote cell proliferation and survival, eventually tumour formation.