Overrepresentation of genes with tumor-specific retention (TSR) in differentially expressed genes (DEGs) between tumor and normal samples. A: Venn diagram of DEG and genes with TSR. B: pie chart of the expression pattern in tumor and normal tissues for genes with TSR. A majority of DEGs are up-regulated in tumors. Non-DEG: genes without differentially expression in tumor and normal tissues; up-DEG: differentially expressed genes up-regulated in tumor tissues; down-DEG: differentially expressed genes up-regulated in normal tissues.