CEACAM5 and neoplasm: When compared with other blood markers, such as CEA (AUC: 0.771,95%CI:0.733–0.810), CA19–9 (AUC: 0.685,95%CI:0.641–0.728), NLR (AUC: 0.690,95%CI:0.647–0.733), and PLR (AUC: 0.744,95%CI: 0.704–0.784), mSEPT9 with an AUC of 0.802(95%CI:0.765–0.840) showed a better diagnostic efficiency, consistent with a previous study [36, 37], indicating that mSEPT9 is specifically elevated in CRC patients and can be used as a tumour marker for CRC diagnosis.