TNMD (tenomodulin) is a type II transmembrane glycoprotein encoded on the X chromosome X functions as a key regulator of tendon development and homeostasis 1. The protein is predominantly expressed in dense connective tissues including tendons, ligaments, and skeletal muscle epimysium, where it serves as an efficient marker of tenocyte differentiation 1. TNMD inhibits angiogenesis and regulates tenocyte proliferation 1. During tendon repair, TNMD plays crucial roles in tendon maturation, differentiation, and extracellular matrix remodeling across multiple stages of the recovery process 2. In pathological conditions, TNMD expression is significantly downregulated in tendinopathy when macrophage-derived inflammatory signals are elevated, with reduced TNMD correlating with impaired tendon stem/progenitor cell differentiation and increased inflammatory infiltration 3. TNMD expression is also modulated by systemic factors; weight loss decreases TNMD mRNA in adipose tissue, and expression correlates with body mass index 4. TNMD polymorphisms (rs4828038) show genetic associations with late-onset preeclampsia susceptibility 5. Additionally, TNMD functions as a molecular marker for layer 6b neuronal differentiation in the developing cerebral cortex 6. These findings suggest TNMD has therapeutic potential in tendon tissue engineering, recovery promotion, and treatment of tendinopathy-related disorders.