In a meta-analysis of hepatocellular carcinoma that included 12 studies with 2117 patients published up to 2017, high blood OPN levels were associated with poor overall survival (OS; OR = 1.84; 95% confidence interval [CI] = 1.54–2.20; p = 0.0001) and disease-free survival (DFS; odds ratio (OR) = 1.67; 95% CI = 1.40–1.98; p = 0.0001) [109]. Here, SPP1 is linked to hepatocellular carcinoma.