The BioPlex (biophysical interactions of ORFeome-based complexes) network is the result of creating thousands of cell lines with each expressing a tagged version of a protein from the ORFeome collection. Immunopurification of the tagged protein and detection of associated proteins by mass spectrometry are the building blocks of the network. The overarching project goal is to determine protein interactions for every member of the collection. A first paper in Cell reports the first ~2,500 experiments (~23,000 interactions). Our current release with more than 5,000 human proteins as baits (~50,000 interactions) is also now available.