Reducing false negatives and false positives by combining Y2H vectors. (A) 67 interactions from five different herpesviruses curated from the literature ("LC") are compared to interactions found in this study. Shown is the fraction of these LC interactions that are found when 1, 2, 3 or 4 vector combinations are used. See text for more details. (B) Similar to (A), our VZV data was compared to large-scale Y2H interactions from HSV1, mCMV, EBV, and KSHV . Shown is the fraction of interologs found by 1, 2, 3, or 4 vector combinations. See text for more details. (C) The fraction of interactions in each combination class that is supported by additional evidence, including literature-curated interactions, large-scale Y2H assays, interologs, or interactions found with alternative constructs. For example, there are 13 non-redundant interactions that have been found in all 4 combinations (NN, NC, CN, CC) of which 9 (= 69%) are supported by previously published evidence or multiple (but different) constructs. See Additional file 1: Tables S1 and S3 for details.