Under Lasso regression (Figure 1C,D), we shortlisted four predictors for HCC including FOS, HAMP, IL13RA2 and LCN2, as well as four predictors for the prognosis of the PD-1 treatment, including SPP1, FOS, CXCL2 and HAMP, ulteriorly cross-tabulating the two to obtain two genes, HAMP and FOS (Figure 1E). This evidence concerns the gene PDCD1 and hepatocellular carcinoma.