The approximate accuracy and coverage of GO term predictions were calculated for every gene in the core or complete interaction networks with at least one known GO term. The GO terms of a gene are predicted using the GO terms of any of its interaction partners (1+), or GO terms shared by at least two to six of its interaction partners (2+ to 6+). Accuracy is calculated as the number of correctly predicted GO terms divided by the total number of predicted GO terms. Coverage is calculated as the number of correctly predicted GO terms divided by the total number of known GO terms associated with each gene. These values are similar for GO annotations at different levels of the GO hierarchy (see Additional data file 3).