Relationship between preoperative CONUT score and CTC in peripheral blood of CRC patients. A. Representative CTC images from included patients 6 and 83. Three-colour immunofluorescence staining based on FITC-labelled anti-CK, PE-labelled anti-CD45, and Hoechst nuclear staining was applied to identify and enumerate CTC from non-specifically trapped WC. B. Correlation analysis between preoperative CONUT score and CTC count. C. Difference analysis of CTC positive rate between preoperative CONUT-low and -high group. Note: Scale bar: 20 μm. Abbreviations: CONUT, controlling nutritional status; CTC, circulating tumour cell; CRC, colorectal cancer; FITC, fluorescein isothiocyanate; PE, phycoerythrin; WBC, white blood cell.