CD133 (prominin-1), a 5-transmembrane glycoprotein, was first recognized in CD34 + progenitor populations from adult blood, bone marrow, and fetal liver cells [10] . Recently, CD133 has been considered an important marker to represent the subset population of CSCs in leukemia, brain tumors, retinoblastoma, renal tumors, pancreatic tumors, colon carcinoma, prostate carcinoma, and hepatocellular carcinoma [11] [12] [13] [14] [15] [16] [17] [18] [19] . Based on immunohistochemical findings, Hilbe and colleagues suggested that CD133-positive (CD133 + ) progenitor cells play a role in the development of tumor vasculature in patients with non-small-cell lung cancer (NSCLC) [20] . More recently, a well-designed study by Eramo and colleagues showed that lung cancer contains a population of CD133 + CSCs able to self-renew and generate an unlimited progeny of non-tumorigenic cells. These CD133 + cells are also resistant to conventional chemotherapy [21] . However, the gene regulation mechanisms in maintaining the self-renewal and drugresistant properties in putative cancer stem-like cells of lung tumors are still unclear.