In order to fairly compare our work with other PPI extraction systems, we use five PPI corpora, i.e., AIMed (Bunescu et al., 2005a), BioInfer (Pyysalo et al., 2007), HPRD50 (Fundel et al., 2007), IEPA (Ding et al., 2002) and LLL (Nédellec, 2005).
most of the evaluation is done on the widely-used AIMed corpus, which contains 177 Medline abstracts with PPI instances, and 48 abstracts without any PPI instances.