The process of calculating the special score system derived from SSBP. A. The definition of special score is similar to that of SSBP, where the red proteins share the parent term that the gene product concerning it is 8, while the counterpart of the green protein is 18. Thus, the red protein pair will have the score 8, meanwhile the green pair corresponds to18. The greater score of the green pair indicates less similarity than the red pair. B, The PPI network between not only human and HV1A2 but also human and EBV. The spot in the picture represents the protein, and the line that links two proteins stands for the interaction between them. The name of the protein is displayed on the spot, while the suffix of each name shows species to which this protein belongs. The human proteins are marked red while the viral proteins are marked yellow. As shown in the picture, the human protein in the protein-protein interaction network is selected out to form two sets, then the distance between the two sets are stored as the distance of the two viruses.