The expression of stem cell biomarker CD133 was increased in these three lung cancer cell lines (A549, H1299, and H1650), while OCT4 were increased in A549 and H1650 cells, flow cytometry further proved that the expression of stem cell markers (CD133, OCT4) was significantly increased in A549-shXPC compared with A549-shCtrl. This evidence concerns the gene POU5F1 and lung cancer.