An investigation of the role of human cationic antimicrobial protein-18/cathelicidin LL-37 (hCAP-18/LL-37) as a putative growth factor for malignant melanoma (MM) cells was conducted. Human MM cell lines overexpressed hCAP-18/LL-37 mRNA and peptide in contrast to HaCaT and chronic myelogenous leukemia cell lines. The peptide was strongly expressed in MM cell lines, moderately expressed in squamous cell carcinoma and weakly expressed (or not expressed) in basal cell carcinoma, precancerous lesions or seborrheic dermatosis. Melanoma cell proliferation, migration and invasion were stimulated in vitro by LL-37. Further studies are needed to elucidate its role in tumorigenesis (Kim, J.E. et al. Br J Dermatol 2010, 163: 959).