SPP1 and hepatocellular carcinoma: To validate the different expression of the five prognostic genes (FYN, PPP1CB, PPP1CC, RAC1, and SPP1) between HCC and adjacent non-tumorous tissues, real-time quantitative-polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were performed to analyze the mRNA and protein expression, respectively.