To improve performance of the predictor of drug-target interaction, feature selection process was carried out. The first step of feature selection is feature evaluation. In this study, mRMR was used to evaluate every feature in original feature set. Listed in Online Supporting Information S5 are two kinds of outputs: the first one is the MaxRel list which shows ranks of features for their relevance to the target; the second is mRMR list showing the mRMR ranks according to the feature order satisfying Eq. 3. In this study, only the mRMR list was used as the results of feature evaluation. Since there are four groups of samples, mRMR was run four times with each for one of them.