All valid SMILES strings generated between epochs 5 and 16 (last fine-tuning epoch) were ranked by beam search scoring. The top five designs according to the beam search score (Fig. ) were deemed synthetically inaccessible by medicinal chemists. This was further highlighted by a machine learning algorithm for retrosynthetic analysis (IBM RXN) which did not find a synthetic route for any of these molecules. Apparently, the CLM failed to meet the fundamental design criterion of synthesizability, suggesting that a different fine-tuning strategy might be required.