POU5F1 and non-small cell lung carcinoma: Under hypoxic conditions, Oct4 and Sox2 induced by hypoxia-inducible factor 1 alpha (HIF1α) and hypoxia-inducible factor 2 alpha (HIF2α) have been found to up-regulate the CD133 promoter in NSCLC cell lines [10] and overexpression of Oct4 and Nanog in NSCLC cell lines have been shown to induce stem cell properties like self-renewal, tumorigenesis, invasion, and metastasis [11].