SPP1 and colorectal carcinoma: The mean OPN, TPS, and CEA serum expressions were also significantly higher in CRC samples compared with controls (OPN: 116.14 ± 36.31 vs. 78.69 ± 16.45 ng/mL, P = 0.032; TPS: 98.77 ± 27.62 vs. 76.40 ± 15.04 U/L, P = 0.018; CEA: 77.17 ± 81.09 vs. 1.95 ± 1.04 ng/mL, P = 0.008).