Papyrus consists of 59,763,781 compound-protein pairs, each associated with at least either one activity value or activity class. Additionally, this represents the data of Papyrus protein space (Figure ) is largely dominated by human proteins, reflecting the abundance of activity values measured for these. Nevertheless, clusters of homologous proteins can be observed, mostly aggregating human rat and mouse protein. As a comparison, the compound space was also visualized (Figure ) with carbon fraction evenly spread across clusters.