CEACAM5 and colonic neoplasm: To further examine the change of serum TC, HDL, CEA and CA19–9 during colon cancer development, we compared the patients in the early stage (I and II) with the ones in the late stage (III and IV), and found that patients with the late stage of colon cancer had significantly lower levels of serum TC and HDL (Fig. 2a), but had significantly higher levels of serum CEA and CA19–9 (Fig. 2b).