The first set of compound-target pairs is obtained from the ACTIVITIES and ASSAYS table . A compound is considered active on a target if it has a pChEMBL value measured in a binding (B) assay (data measuring binding of a compound to a molecular target, e.g., Ki, IC50, Kd) or functional (F) assay (data measuring the biological effect of a compound, e.g., % cell death in a cell line, rat weight). ChEMBL provides pChEMBL values, i.e., the negative logarithmic representation of the molar activity values, for selected concentration-response activity values (IC50, EC50, XC50, AC50, Ki, Kd, potency). All compounds are mapped to their parent compound through the MOLECULE_HIERARCHY table. The information of the parent compound is subsequently used to identify the compound and the information about the salt form is dropped. If there is more than one activity measurement for a compound-target pair, the pChEMBL values are aggregated into mean, Each compound-target pair is assigned a drug-target interaction type (DTI). The different interaction types are shown in Table . If the compound-target pair is in the DRUG_MECHANISM table, it is considered to be a known and relevant compound-target interaction. The pairs are annotated as D_DT (drugs) or C<p>_DT (clinical candidates) based on the maximum clinical phase <p> that the compound reached. The remaining pairs are annotated with DT if the target is in the DRUG_MECHANISM table, i.e., if the target plays a role in the disease efficacy of at least one compound, and with NDT otherwise. DT compoundtarget pairs are kept as 'comparator' compounds. Note that these may include approved drugs and clinical candidates when they are approved for another target but the mechanism of action with the given target is unknown. All NDT pairs are discarded and do not appear in the final dataset.