LL-37

Research Overview

The available evidence on LL-37 is limited and primarily consists of recent laboratory studies and small observational trials, with most clinical trials either withdrawn or terminated. The research spans several therapeutic areas but lacks robust clinical evidence.

Key Laboratory Studies

Recent research in 2026 has explored LL-37's mechanisms across different conditions. One study investigated LL-37's role in osteosarcoma, finding that it may inhibit tumor progression through suppression of cholesterol synthesis pathways (PMID: 42388271). Other laboratory work examined the physical properties of LL-37 and similar peptides, including their interaction with cell membranes (PMID: 42439051) and their potential anti-infective mechanisms involving hydrogen sulfide (PMID: 42386743).

A corrigendum was published regarding previous research on LL-37's role in rosacea-like skin inflammation, though the original study details are not provided in the current evidence (PMID: 42420052).

Clinical Research

The clinical trial evidence for LL-37 is notably weak. Of five registered trials:

• NCT03923218: A completed observational study examining how smoking and vitamin D3 supplementation affect LL-37 levels, though results are not provided
• NCT04404335: A completed observational study on LL-37 as a biomarker in periodontal disease treatment, with no available results
• NCT00788320 and NCT03270709: Both vitamin D-related studies were withdrawn or terminated
• NCT01372995: A Phase 2 trial of vitamin D in ICU patients was completed, though its connection to LL-37 research is unclear

Observational Studies

Two small studies examined LL-37 in specific patient populations. One pilot cross-sectional study investigated vitamin D receptor genetics and LL-37 levels in tuberculosis patients (PMID: 42389554). Another looked at LL-37 levels in the gingival fluid of diabetes patients with periodontitis, examining relationships with vitamin D status (PMID: 42388571). Both studies had limited sample sizes typical of pilot research.

Evidence Limitations

The current evidence base for LL-37 is characterized by early-stage research with significant gaps. Most clinical trials have not been completed successfully, and published studies are primarily laboratory-based or small observational studies. No large-scale randomized controlled trials demonstrating clinical efficacy are available in this evidence set.

This synthesis is for informational purposes only and does not constitute medical advice. Consult healthcare providers for clinical decisions.