S100A1 and hepatocellular carcinoma: 13 of the 21 family members were found to be highly expressed in HCC tumor samples, including S100A1, S100A2, S100A3, S100A4, S100A5, S100A6, S100A10, S100A11, S100A13, S10016, S100P, and S100Z (Figure 1A).