MTOR and cancer: Specifically, GPCRs can regulate effectors such as enzymes and ion channels mentioned in the parts of glucose.31–33 For example, by activating MAPK, PI3K, mTOR, etc., the changes in cell metabolism can promote the progression of cancers.117–122 The MAPK, PI3K, and mTOR signal pathways play important roles in maintaining cell proliferation, growth, and survival,123,124 and are often abnormally altered in various cancers (Fig. 2).