BMI1 and neoplasm: Similarly, hybrid cells derived from spontaneously fused non-small cell lung cancer cells and bone marrow-derived mesenchymal stem cells exhibited an increased expression of the stem cell marker CD133 and overexpression of stemness factors, including OCT4, NANOG, BMI-1, NOTCH1, ALDH1 and SOX2, which was associated with an increased pneumosphere-forming capacity and tumor-forming ability [20].