As for the applicability domain of the RPLC classification model, the 95% leverage threshold of the training set was 0.209 (Figure ). In total, 102 compounds from the test set (i.e., 6.9%) had a leverage with the training set that was higher than 0.209, of which 31 cases had leverage values above 1. Out of these 102 cases only 10 were wrongly classified and had leverage values ranging between 0.209 to the most extreme (i.e., 809.255), showing that in this case higher leverage values did not necessarily mean that the model would have a higher error. However, it should be noted that cases with a very large leverage should be considered with extra care, as they may have a higher level of uncertainty.