Moreover, the phosphatidylinositol 3-kinase (PI3K)/mTOR pathway is constitutively activated in different types of cancer and involves a number of tumor suppressor genes including PTEN, LKB1, TSC1, TSC2, Rb1 and p53, making this pathway a promising target for anti-cancer therapies[39–41]. Here, RB1 is linked to neoplasm.