PTEN is one of the most common tumor suppressors frequently mutated in human cancers, and it is a lipid phosphatase that cleaves the D3 phosphate of the second messenger phosphatidylinositol 3, 4, 5-trisphosphate and thus negatively regulates the phosphatidylinositol 3'-kinase (PI3K) pathway [30–32]. Here, PTEN is linked to cancer.