ALDH1A1 and non-small cell lung carcinoma: The aim of our study was to determine expression of EMT-inducing transcription factors (BMI1, TWIST1), CSC markers (CD133, ALDH1A1), and epithelial markers (EpCAM) in primary tumors and matching whole blood samples as well as in CTCs of patients of NSCLC and to evaluate possible associations between marker expression within primary tumors, within whole blood and between tumors and blood.