KRT19 and colorectal carcinoma: Therefore, we carried out a prospective study, called COLOSPOT, on patients with untreated metastatic CRC, about to receive FOLFIRI (folinic acid, fluorouracil, and irinotecan) and bevacizumab as first-line therapy, to further investigate the clinical utility of viable CTCs detected with the CK19-EPISPOT assay.