Since SPOTLIGHT provides the option to modify an existing molecule, we used this to find out whether SPOT-LIGHT can suggest alterations to a known molecule from the random set of its substructures. Fragment modification is often used in medicinal chemistry to diversify the existing repertoire, with the hope of landing on a more potent drug molecule. We therefore fragmented known ligands by a fixed percentage randomly and regrew them to observe the similarity to the original molecule, and any changes made. Even when a fixed fraction of the original molecule is retained, the actual amount of similarity with the original structure differs for each new ligand. As a representative example, Figure shows the structures of different amounts of fragmentation (or retention) of a specific ligand that is known to bind to HSP90. Figure shows the mean similarity of the regrown molecule to the original one against the percentage retention after fragmentation. The result shows, as expected, that preserving a larger fraction of the molecule results in getting back (after regrowing) molecules that are more similar to the original molecule. This shows that despite the stochastic nature of our method and the vastness of the chemical space, tuning between similarity to a given structure and binding strength is indeed possible. Regrown molecules often bind stronger than the original molecule in terms of the SPOTLIGHT score which indicates the strength of binding.