S100A9 and hepatocellular carcinoma: Except for MTMR2, the other nine genes comprising the signature were previously reported in HCC and their functions could be roughly classified into five categories, including cell cycle (CDCA8), chronic inflammation (S100A9), anti‐oncogene (ANXA10), energy metabolism (G6PD, SLC1A5, SLC2A1), and extracellular matrix organization (SPP1, PLOD2, and MMP1).