Understand the source comparison
LL37 / LL-37 Nomenclature: Literature Comparison
Understanding how LL37 and LL-37 appear across published research clarifies that the nomenclature difference is purely stylistic. The table below compares how each name variation is used in peer-reviewed literature, regulatory databases, and commercial peptide
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This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- Understanding how LL37 and LL-37 appear across published research clarifies that the nomenclature difference is purely stylistic. The table below compares how each name variation is used in peer-reviewed literature, regulatory databases, and commercial peptide catalogs. Demonstrating functional equivalence.
- LL37
- Primary name in North American immunology journals; standard in PubMed-indexed articles post-2005
- ~8,200 PubMed citations as of 2026
- 37-amino-acid cathelicidin fragment, MW 4493.3 Da, sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
- Preferred for catalog consistency and database searches
- LL-37
- European journal formatting; common in dermatology and wound-healing literature pre-2010
- ~6,400 PubMed citations (many duplicate entries with LL37)
- Identical sequence, molecular weight, and structural characteristics
- Functionally interchangeable. Hyphen is typographic only
- hCAP-18
- Refers to the 18 kDa precursor protein from which LL37 is cleaved; used when discussing gene expression or proteolytic processing
- ~1,100 PubMed citations
- Full-length 134-amino-acid cathelicidin precursor; becomes LL37 after proteinase-3 cleavage
- Technically distinct. HCAP-18 is the inactive precursor, not the active peptide
- FALL-39
- Historical name from early cathelicidin research; rarely used after 2000
- <200 citations, primarily 1995–2005
- Slightly longer 39-residue fragment including two additional N-terminal residues
- Obsolete nomenclature. Modern literature uses LL37 exclusively
- CAP18
- Shortened precursor name; used interchangeably with hCAP-18 in gene expression studies
- ~900 citations, mostly molecular biology contexts
- Refers to precursor gene product before cleavage
- Precursor only. Not the mature active peptide
- The critical distinction is between precursor names (hCAP-18, CAP18) and the mature active peptide (LL37, LL-37). The hyphen difference between LL37 and LL-37 carries zero biological significance. Both refer to the same 37-amino-acid active fragment. Researchers ordering peptides should verify the amino acid sequence rather than relying solely on the catalog name, but reputable suppliers like Real Peptides maintain nomenclature consistency across documentation and certificates of analysis.