LL-37

LL-37 is an antimicrobial peptide with angiogenic activity. It corresponds to the C-terminal sequence (134-170) of the human cathelicidin antimicrobial protein hCAP18/LL-37 and is extracellularly released from hCAP18/LL-37 by proteolytic processing. hCAP18/LL-37 is an effector of the innate immune system and is expressed in leukocytes and epithelial cells where it is upregulated in association with inflammation and injury. An overexpression of hCAP18/LL-37 in a series of breast carcinomas could be demonstrated. LL-37 has been suggested to stimulate epithelial cell proliferation partially through formyl peptide receptor-like 1 (FPRL1) since blocking the receptor with pertussis toxin decreased the proliferative effect of LL-37 by approximately 50 %.