ProteomicsDB (www.ProteomicsDB.org) is an in-memory database initially developed for the exploration of large collections of quantitative mass spectrometry-based proteomics data. To date it contains data across hundreds of human tissues, body fluids and cell lines including but not limited to transcriptomics data, protein-protein interaction information, functional annotations, viability results, drug selectivity data and synthetic and predicted reference mass spectra. Accompanied with a rich user interface for real-time exploration, the extended data foundation transformed ProteomicsDB into a multi-purpose resource for life science research.