KRT19 and cancer: In the present study, we applied this combination to blood samples of NSCLC patients and asked whether, in addition to well-established gene markers for epithelial cells (EpCAM and CK19), further markers for ciliated epithelial cells, for the epithelial-to-mesenchymal transition (EMT), and for cancer stem cells (CSC) could indicate the presence of CTCs and may have prognostic relevance in this type of cancer.