GCDH and hepatocellular carcinoma: Transcriptomic profiling across multiple public databases, including The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and JP Project of the International Cancer Genome Consortium (ICGC-LIRI-JP), revealed the down-regulation of GCDH in HCC tissues compared to nontumor tissues (Fig. 8A to C).