Previous studies have confirmed that miR-221 also inhibits the expressions of the PTEN and cyclin-dependent kinase inhibitor family members (Le Sage et al., 2007; Park et al., 2011; Callegari et al., 2012), whereas anti-miR-221 upregulates the expression levels of corresponding tumor suppressor factors, which could be the molecular mechanism underlying the anti-tumor effect induced by anti-miR-221 in this study. Here, PTEN is linked to neoplasm.