EDD2 (E3 identified by differential display), also known as UBR5 or hHYD, is an evolutionarily conserved homologous to E6-AP carboxyl terminus bearing E3 ubiquitin-protein ligase of the N-rule pathway (1) and homolog of Drosophila hyperplastic discs (Hyd), a Drosophila tumor suppressor involved in controlling tissue growth and differentiation (2, –, 4). This evidence concerns the gene UBR5 and neoplasm.