Updated project metadata. The ProteomeTools project aims to derive molecular and digital tools from the human proteome to facilitate biomedical and life science research. Here, we describe the third iteration of the generation and multimodal LC-MS/MS analysis of >305,000 synthetic non-tryptic peptides representing HLA Class I & II ligands as well as peptides derived from the N-terminal proteases LysN and ApsN. This resource will be extended to 1.4 million peptides and all data will be made available to the public in ProteomicsDB.