Fibromodulin (FMOD) is a small leucine-rich proteoglycan (SLRP) that functions primarily in extracellular matrix organization and collagen fibrillogenesis 1. FMOD regulates cell adhesion and modulates transforming growth factor-beta (TGF-β) signaling pathways 1, with demonstrated involvement in the TGF-β/Smad signaling cascade 2. Mechanistically, FMOD suppression reduces cell proliferation, adhesion, and migration in non-small cell lung cancer through TGF-β pathway inhibition 2, while low FMOD expression facilitates plasmacytoid dendritic cell maturation via increased IL-3 production 3. Clinically, FMOD dysregulation associates with multiple pathologies. Genetic variants in FMOD, particularly the potentially pathogenic p.(Tyr42Ser) missense variant, correlate with prostate cancer and benign prostatic hyperplasia susceptibility 1. FMOD serves as a fibrosis-associated biomarker in heart failure and multiple cancer types 4, and contributes to glioblastoma prognosis through ferroptosis-related mechanisms 5. In osteoarthritis, FMOD downregulation impairs chondrocyte proliferation and increases apoptosis via ERK pathway activation 6. Additionally, FMOD overexpression alleviates post-traumatic brain injury depression through PI3K/AKT/mTOR pathway activation 7, and its upregulation in senescent vascular smooth muscle cells promotes atherosclerosis-associated phenotypic modulation 8.