Supplementary material, section S2 shows the linear model that was used in order to calculate the RI_PEG_LM descriptor in explicit form. It should also be noted that when this model was trained, the training set did not contain the molecules that are contained in the data sets for IL-based SP. This way we ensured that there was no "data leak" and the molecules used for testing were not seen by the model at any stage of training.