Further analysis showed CRC patients with CEA level at least 5 ng/mL (the standard cut-off value) had elevated the levels of PC and PCT, but this phenomenon was not observed with MPV (Fig. 2b); In addition, PC, MPV and PCT levels showed no significant correlation with CA19-9 level of at least 37 U/mL (the standard cut-off value) (Fig. 2b). Here, CEACAM5 is linked to colorectal carcinoma.