In the case of troglitazone, the success rate can be improved significantly by using DeepSMILES (Figure ), another string-based molecular representation that doesn't involved matched parenthesis and integers denoting ring-closures. However, using DeepSMILES does not increase the success rate for celecoxib or tiotixene. Finally, using SELFIES does not increase the success rate for any of the three molecules. It is very likely that the performance of the string-based GA searches can be improved significantly by using more sophisticated algorithms. The main point for the purposed of thus study is that the molecular representation is one of the factors that can complicate the exploration of chemical space.