Epigenetic inhibitors can partially restore a normal expression pattern to tumor cells. Genes that showed tumor-specific changes in expression in TCGA colon RNA-seq samples (left), TCGA pancreatic RNA-seq samples (right, top), plus differentially expressed genes identified by comparison of normal to tumor pancreatic cell lines (right bottom) were analyzed for responses to drug treatments; see Additional file 6. In the T/N columns, green indicates that the gene was downregulated in the tumor cells whereas red indicates the gene was upregulated in the tumor cells. The blue brackets indicate genes that were downregulated in the tumor cells and upregulated by the drugs (resulting in an expression level closer to that in normal cells) whereas the black brackets represent the genes that were upregulated in the tumor cells and downregulated by the drugs (resulting in an expression level closer to that in normal cells). The color scale indicates the fold change of gene expression in HCT116 or PANC1 cells after treatment with ICG-001 (ICG) or C646.