Over the last few years, the establishment of thrombin recognition sequences in peptides has expanded fusion protein technology. In light of this, the ten amino acid (YCLVPRGNCY) cyclopeptide was synthesized and analyzed. Cyclopeptides are more permeable and experience superior biological activity due to the high amounts of cis amide bonds and the lack of ionizable amino- and carboxy- termini. Cyclic configurations may also be beneficial for fusion protein spacing and separation. Accordingly, these molecules are attractive candidates when considering synthetic fusion protein linkers and thrombin recognition sequences. This regulated protease activity allows for controlled cleavage and separation of specific proteins from fusion partners and markers. It is conceivable that this technology expands the therapeutic potential of protein drug delivery. This book, therefore, provides a novel method for researchers to examine when developing and delivering fusion proteins to target sites.