SPP1 and hepatocellular carcinoma: In consistent with our previous study in HCC tissue [18, 22], we found that OPN level in tumor tissues was significantly associated with HBsAg (P = 0.024), vascular invasion (P = 0.033), and tumor differentiation (P < 0.001) (Table 1), as well as prognosis of HCC patients (Supplementary Figure 10A and 10B).