Targeted overexpression or knockdown of miR-221/222 in NSCLC cells revealed the essential roles of miR-221/222 in regulation of lung cancer cell proliferation, mammosphere formation, subpopulation of CD133+ CSCs and the expression of stemness genes including OCT4, NANOG and h-TERT. The gene discussed is PROM1; the disease is non-small cell lung carcinoma.