The compounds designed from the three ChemDiv libraries and the two Life Chemicals libraries (Table ) cover similar regions of the chemical space with the t-SNE based on MACCS Keys (Figure ). These observations are expected because chemical libraries from the same provider could share structural features detected with the MACCS Keys. However, differences are observed with the visualization based on ECFP4 (Figure ), associated with the differences in resolution between the two fingerprints. Compounds from FooDB and UNPD-A cover similar areas with both representations; the reason for this could be the account of the rest of the libraries being focused on small, less complex molecules.