Given that the 'Ring Breaker' models cannot always predict the synthesis of unsubstituted fragments owing to template specificity for the unsubstituted furan and benzene (Figure ), we additionally applied the 'Ring Breaker' models to a set of 2039 approved drugs obtained from the DrugBank database. By doing so, we exemplify that in the case of complete structures, and not only unsubstituted fragments obtained from ZINC, 'Ring Breaker' is able to predict ring forming steps for their synthesis. Figure shows that the 'Ring Breaker' model trained on the Reaxys dataset consistently predicts more applicable templates in the top 50 predictions, and with a lower rank than the model trained on the USPTO dataset. This is in line with that observed previously as shown in Figure .