The present invention provides, among other things novel peptides compositions comprising provided peptides, and methods for using provided peptides and compositions. In some embodiments, the cyclic peptide comprises a linkage between amino acids (e.g., between any of the two amino acids). In some embodiments, the present invention provides compositions comprising one or more peptides according to formula I. In some embodiments, provided compositions comprise a peptide according to formula I and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical composition further comprises one or more pharmacologically acceptable excipients selected from a polymer carrier, a disintegration agent, a lubricant, a solvent, or a swelling agent.La présente invention concerne, entre autres choses, de nouveaux peptides, et des compositions pour traiter des maladies.