IGF1 and gastric cancer: Because of the evidence that PTEN functions as a protein phosphatase targeting IRS1 [23], a key mediator to transfer a survival signaling from IGF stimulation to phosphorylated Akt, it can be inferred that PTEN protein phosphatase activation-dependent regulation of a NEDD4/PTEN/IRS1 signaling contributes to the oncogenic role of NEDD4 in IGF1 signaling-driven GC.