Z-FA-FMK can irreversibly inhibit cysteine protease and also inhibit effector caspases.

Acetyl-(Cys4,D-Phe7,Cys10)-α-MSH (4-13)

Levitide is a neurohormone-like peptide, can be isolated from skin secretions of the South African frog Xenopus laevis. Levitide comes from preprolevitide, is 88 residues long and contains contains the levitide peptide at the C terminus (Glu-Gly-Met-Ile-Gly-Thr-Leu-Thr-Ser-Lys-Arg-Ile-Lys-Gln-NH2) and the putative signal sequence at the N terminus.