Lung cancer stem cell markers include the transcription factor SOX2, the metabolic marker aldehyde dehydrogenase isoform 1 (ALDH1), and the cell surface markers CD133, CD44, CD166, and ABCG2 (Ho et al., 2007; O'Flaherty et al., 2012). This evidence concerns the gene ABCG2 and lung carcinoma.