CEACAM5 and neoplasm: Moreover, PCF sample no. 1 displayed a high CEA level of 531 ng/ml and was therefore considered a MC, yet, surgical pathology classified this tumor as serous (Table S3) and the rheological behavior of this sample matched that of flow curve type I. These results underscore the wide variability and suboptimal accuracy of CEA-based diagnosis, as well as the need for alternative and more precise diagnostic tools17.