Disulfide-constrained peptides are small (15-75 amino acid residues) that have gained interest as promising scaffolds for development of peptide leads for therapeutically relevant targets including pain, cancer, multiple sclerosis and diabetes. In particular, members of the inhibitory cystine knot family have gained interested due to their intrinsic stable properties brought about by the cystine knot and the plasticity of the loops protruding from the core of the peptide. We are capitalizing on these intrinsic properties to build a powerful display platform able to produce constrained peptide leads for a range of clinically validated targets.