In the present study, we evaluated the MAOA expression levels in HCC patients compared with non‐cancer groups by integrating in‐house tissue microarray data and datasets downloaded from Gene Expression Omnibus (GEO), Array Express, Sequence Read Archive (SRA), Oncomine, the Cancer Genome Atlas (TCGA), and the Genotype‐Tissue Expression project (GTEx). This evidence concerns the gene MAOA and hepatocellular carcinoma.