Figure 1: Possible pathways for growth factor mediated tumorigenesis. Activation of receptor can lead to cell proliferation, survival, angiogenesis, and metastasis via four possible pathways; the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, Ras/Raf/mitogen-activated protein kinase (MAPK) pathway, nitric oxide synthase (NOS), and prostaglandin (PG) involving phospholipase Cγ (PLCγ)/protein kinase C (PKC) pathway and signal transducer and activator of transcription (STAT) pathway.