Given that the chemical space is huge, our sampling, although efficient, was not adequate to generate the known ligands. However, we found that SPOTLIGHT generates ligands with important scaffolds that are also found in the known ligands. For all analyses that involved known ligands of HSP90, we used a set of the top 50 molecules (by Kd values) from the BindingDB 52 database. It uses most of the smaller ligands as substructures to be built on. Figure shows novel molecules which contain over 70% of the substructure of some known molecule. Larger known molecules are unlikely to be obtained with significant similarity, (although we find common substructures) due to the sheer randomness of the algorithm and divergence of the possibilities at each stage of generation.