Further evaluation of the essentiality of the PPI will be necessary when the targets are pursued further. For PPI-Nem, many of the PPIs found did not have an RNAi phenotype available, causing their scores to be lower. Interactions where only one protein has a severe RNAi phenotype could be promising drug targets, but more RNAi experimentation should be done to determine the RNAi phenotype of the other protein in the interaction pair. For PPI-Indel, nearly all the PPIs that ranked highly had a severe RNAi phenotype. Co-localization of proteins can be considered a prerequisite for direct PPIs. In the absence of specific antibodies to candidate proteins, co-localization of mRNA expression using ISH is an alternative indicator for PPIs. Tissue-specific localization of protein expression in B. malayi has been used to confirm gender regulated protein expression and as pointer to protein function. While using the PPI database originating from C. elegans to infer PPIs in the parasitic species, we used ISH and synthetic oligonucleotides to study the localization of mRNAs of four pairs of candidate PPIs in two species with very distinct mode of parasitism, the human parasite B. malayi and/or the plant-parasite M. incognita. This technique allowed tissue-specific localization of the mRNAs of protein pairs in egg cells and developing embryos or in the anterior Pazopanib intestines and pharynx. As part of the development process, targets that yielded promising results via ISH should be tested using alternative techniques such as yeast two-hybrid assay or co-immunoprecipitation to confirm the protein-protein interaction, and biophysical techniques should be used to determine KD. Development of a two-hybrid assay for these PPIs also provides a means for screening small molecule drugs that could potentially block the protein-protein interaction. Certain types of proteins are considered better drug targets than others. Based on Hopkins�� work, druggable proteins are targets to which drugs that follow Lipinski��s rule-of-five bind. Almost half of the targets found by Hopkins et al, fall into six main protein catagories: G-protein coupled receptors, serine/ threonine and tyrosine protein kinases, zinc metallopeptidases, serine proteases, nuclear hormone receptors, and phosphodiesterases. For PPI-Nem, the druggability was evaluated, but for the R428 PPI-Indel group, the druggability was added to the scoring function to allow differentiation among a much larger dataset. For PPI-Nem, three of the PPIs had domains that were considered druggable.