We now describe our experimental design to illustrate these failure modes. Our goal is to generate molecules that are active against some biological target. We selected three wellknown targets; Janus kinase 2 (JAK2), epidermal growth factor receptor (EGFR) and dopamine receptor D 2 (DRD2) for which we downloaded data from ChEMBL . We preprocessed the data to obtain binary classification tasks. Information about the data is displayed in Table .