The systematic flow of HPI prediction. The Homologous HPI (HomoHPI) were obtained from the HPI databases (HPIDB, BIPS) by BLAST method, followed by applying the DDI filter and keyword filter. After applying these filters, the number of HPIs was trimmed from 138842 to 1863 and then to 118, respectively. The pie charts on the right depict the components of PPIs obtained from each procedure. The intraspecific interactions were extracted from 8 PPI databases (VisANT, Reactome, InteroPorc, IntAct, DIP, MPIDB, MINT, HPRD) and narrowed down to non-redundant data.