This 37 residue peptide is a very effective antimicrobial agent in rabbits. The CAP-18 cathelicidin-derived peptide kills bacteria by disrupting the bacterial membrane. It has a potential for the treatment of bacterial infections in normal and immunocompromised persons and individuals with cystic fibrosis. In experiments it demonstrates the greatest activity against over 20 clinical strains of Pseudomonas aeruginosa. Homologs of CAP18 in other species include humans (FALL39/LL37), mice (mCRAMP), rats (rCRAMP), and sheep (SMAP29 and SMAP34).