Penalized logP was used as one of the target property types in the optimization processes. However, exploring using these values does not show substances' activity on VEGFR-2. With penalized logP, the algorithm may find very hydrophobic molecules which have high target values. Therefore, the objective function of the BO process was chosen to be whether the predicted pIC 50 value resulted from the QSAR model, or the dual value calculated using the formula: