Subsequent immunohistochemistry (IHC) experiments validated that S100 calcium-binding protein A9 (S100A9), annexin A3 (ANXA3), nicotinamide phosphoribosyltransferase (NAMPT), carboxylesterase 2 (CES2) and calcium activated chloride channel A1 (CLCA1) were differentially expressed between paired CRC and adjacent normal samples (P<0.05). Here, CES2 is linked to colorectal carcinoma.