S100A9 and hepatocellular carcinoma: Next, we conducted LASSO Cox regression with the 28 genes and acquired seven robust genes (TMPRSS6, SPP1, S100A9, EPO, BIRC5, PLXNA1, and CDK4) that were significantly correlated with the OS of HCC patients, and the selection of the tuning parameter in the LASSO model is shown in Figure 3F.