Consistent with its role as a tumor suppressor, PTEN re-expression decreased relative PC invasiveness (Fig. 3C), clonogenicity (Fig. 3E), chemotaxis (Figs. 4A&C) and tumor formation (Fig. 6F), whereas PTEN knockdown in isogenic 22Rv1 cells increased clonogenicity (Fig. 3E). This evidence concerns the gene PTEN and neoplasm.