GAD1 and hepatocellular carcinoma: GAD1, SPP1, and WFS1 were upregulated, whereas GOT2, EHHADH, and APOA1 were downregulated in HCC samples compared with peri-tumor controls, and this was consistent with the results in the ICGC, GSE14520, GSE54236, GSE107170, and GSE36376, validation datasets (Figures 4A–E).