(1) Data collection and preprocessing Structures of kinase-inhibitor complexes were collected from the KLIFS database (downloaded on 2019-11-06), which offers superimposed kinase structures from the PDB with 85 residues defined as kinase binding site. In KLIFS, several entries can exist for one PDB code, since crystal structures were split into all existing alternate location models and all kinase-domain-containing chains of heteromeric protein complexes. Each KLIFS entry comes with details on the species, kinase, kinase group, PDB code of the complex and the ligand, sequence alignment of the 85 binding site residues, DFG conformation (in, out, or out-like), ligand position (within or outside the main pocket), and KLIFS quality score. The latter ranges from 0 (bad) to 10 (flawless) and describes the quality of the alignment as well as structure based on each structure's alignment to a reference as well as its number of missing residues and atoms, respectively.