| Index | Ligand Name | Structure | PDB code | Compound Potency nM |
| 1 | acf | Crystal structure of human dipeptidyl peptidase IV (DPPIV) complexed with cyanopyrrolidine (C5-pro-pro) inhibitor 21ag | 2g5t | 0.82 |
| 2 | axd | Crystal structure of human dipeptidyl peptidase 4 (DPP IV) with potent alkynyl cyanopyrrolidine (ABT-279) | 2i03 | 1 |
| 3 | adf | Crystal structure of human dipeptidyl peptidase IV (DPPIV) complexed with cyanopyrrolidine (C5-pro-pro) inhibitor 21ac | 2g5p | 3.8 |
| 4 | 417 | Human dipeptidyl peptidase IV/CD26 in complex with a cyclohexalamine inhibitor | 2p8s | 21 |