To test the robustness of our algorithm in classifying binding site residues (either hotspots or non-hotspot) we calculated the percentage of recall, by comparing between the apostructure scanning output for each system and the actual hotspots identified from the holo-complex crystal structures. Finally, we provided insights on multiple fragment-to-lead growing strategies from literature and compare the strategies to the hotspot classifications that are detected by FP-score. The novelty of FP-score in classifying binding site residues, also demonstrates the potential of using FMOPhore to determine the selectivehotspot residues for developing selectivity strategies between related protein family.