Resolving the evolution of the Ubiquitin in the genome of Pestivirus suggested that the virus hijacked Ubiquitin-related sequences in two consecutive events [41] . A browsable table is available at www.protonet.cs.huji.ac.il/ virost/tables/UniRef90-Class1.html. Figure 2 shows a prototypic case of viral proteins that resemble the host protein. Interleukin 10 (IL-10) inhibits the induction of pro-inflammatory cytokines. IL-10 was found in many viruses including Epstein-Barr virus (EBV), equine herpesvirus (EHV) and cytomegalovirus (CMV) [42] . Presumably, the gene product protects the infected cells from the host defense mechanism. An extended cluster of IL-10 (Table 1) covers 20 viruses and 96 cellular organisms (UniRef50_P22301). Representatives of viral and metazoan proteins are shown by the multiple sequence alignment (MSA) ( Figure 2B ). Most of the variations in the viral and metazoan protein reside in the sequence of the N-terminal that covers the signal peptide ( Figure 2B ). Traces of a genomic organization of the host in the viral genome were reported. For example, IL-10 like sequence from the gammaherpesvirus ovine herpesvirus 2 includes 5 exons and 4 introns [43] .