Comprehensive analysis of these functional clusters found those DUPs were involved in many cancer-related biological functions, such as cell–cell adhesion in cluster 1, regulation of the assemble of proteasome complex and UPS in clusters 2 and 3, transcriptional and translational regulations in cluster 6, cell signal transduction in cluster 2, and anti-tumor drug metabolism in cluster 8 (Table 2). This evidence concerns the gene HMBS and cancer.