Recent studies have demonstrated that miR-21 increases tumor cell proliferation, migration, and invasion through targeting PTEN [20], a tumor suppressor gene that is an antagonist of phosphatidylinotidol 3-kinase (PI3K) by removing the 3′-UTR phosphate of phosphatidylinositol 3,4,5-trisphosphate (PIP3). This evidence concerns the gene PTEN and neoplasm.