As noted in Section 2. The PubChem database Two closely related global efforts, SureChEMBL and PDBBind, also deserve mention. SureChEMBL 21 is a project that collects compounds from patents and makes them searchable and downloadable. Its automated curation platform enables extensive coverage of existing patents but does not associate compounds with binding affinity data and therefore does not overlap with BindingDB. PatCID 22 is a recently announced resource that is similar in spirit to SureChEMBL. The PDBBind database collects protein-small molecule crystal structures from the Protein Data Bank and joins them with their respective binding affinity data in order to provide a curated dataset uniting three-dimensional structures and affinities for ~23,000 protein-ligand complexes (, accessed 7/3/2024). This number is much smaller than the 2.9 million measurement scope of BindingDB because cocrystal structures have been determined for only a fraction of protein-ligand pairs for which affinity data are available. In particular, whereas BindingDB contains binding data for many congeneric ligand series, PDBBind is expected to contain data for only one or a few compounds from any given congeneric series. On the other hand, PDBBind contains binding data for a number of protein-ligand complexes in the PDB that are not present in BindingDB, making these complementary resources. It is also worth mentioning PLINDER, a new collection of protein-small molecule structural data (but not affinities) designed for training and testing AI methods .