These signals consist of Ras/Raf/MEK/ERK and Ras/PI3K/Prime Time Entertainment Network (PTEN) / Protein kinase B (AKT, also known as PKB) / mammalian target of rapamycin (mTOR) signaling cascades, and are known to play a significant role in regulating cancer cell growth and survival [42,43,44,45]. Here, MTOR is linked to cancer.