To better investigate the mechanism by which PTEN affects metastatic potential in colon cancer, we evaluated the knockdown of PTEN by RNA interference-induced PTEN gene silencing, and found that blockage of PTEN expression not only enhanced the activity of PI3K and its downstream targets Akt, but also promoted proliferation and invasion in colon cancer cell lines. Here, PTEN is linked to malignant colon neoplasm.