SPP1 and hepatocellular carcinoma: The expression levels of 4 proteins B2M, GDF-15, IGFBP-2, OPN has also been determined for HCC patients (mean concentration of 8.024, 1.972, 16.367, 1.052 μg/ml) and Normal controls (6.231, 1.266, 10.106, 0.714 μg/ml), and the fold change differences ranged from 1.29 to 1.62.