Additionally, Figure Hence, the commonality in SCINS classes does not imply chemical similarity, which is to be expected since SCINS ignores most of the chemical information. Moreover, nearly 88.3% of Enamine Diverse molecules have 2-4 rings, 2-3 ring assemblies, and 1-2 chain assemblies, while this range covers only about 59.7% of ChEMBL. Hence, Enamine REAL Diverse covers this particular part of SCINS space especially densely. This result is similar to the results obtained in the scaffold analysis of the CAS database, where the authors found that half of the compounds can be described by only 143 framework shapes . It is also similar to the analysis that Bemis and Murcko conducted with the introduction of the molecular frameworks, which showed that more than half of the known drugs at that time were described by only 32 scaffolds . both curves are far from the diagonal, indicating a heavy-tailed distribution (as also seen in Supplementary Figure and Supplementary Figure ), the one for Enamine encloses a smaller AUC (0.939, while that for ChEMBL is 0.985). Additionally, 50% of the dataset is contained in only 0.2% of the SCINS classes in ChEMBL but 3.8% in Enamine. The scaled Shannon entropy (SSE) also suggests that compounds in the top N most populated SCINS classes are more equally distributed across those N classes in the case of Enamine Diverse compared to ChEMBL, as shown in Table . Hence, the three observations agree and confirm the more even distribution of molecules across the SCINS classes for Enamine REAL Diverse compared to ChEMBL.