Cyclo(RADfK) and c(RADfK) are cyclic peptides primarily used in the field of biomedical research and drug development. These compounds are often employed in the study of peptide-protein interactions due to their stable cyclic structure, which mimics natural peptide conformations. They are particularly valuable in the development of targeted therapies, as their ability to bind selectively to specific proteins can be harnessed to design drugs with high specificity and minimal off-target effects. Additionally, these peptides are utilized in the development of diagnostic tools, where their binding affinity can be exploited to detect specific biomarkers in biological samples. Their stability and resistance to enzymatic degradation make them suitable candidates for in vivo applications, including imaging and therapeutic delivery systems.