The chemistry in Fig. shows similar disproportionation with ChEMBL, as expected, dominating unique content by over 1.2 million. While this is skewed by the BioAssay subsumation of ~0.5 million, most will be a consequence of extracting ~35K unique PMIDs. For BindingDB most of their 153K unique structures are from the ~200,000 protein-ligand binding data points curated 1,100 US Patents during 2019 (n.b. these will eventually be subsumed into ChEMBL release 26). We can further rationalise the proportionality between compounds and PMIDs by noting that GtoPdb extract on average ~ 1 lead compound perpaper, ChEMBL ~14 per-paper with BindingDB extracting similar numbers from papers but increasing to ~ 40 per-patent.