CHI3L1 and Insulin resistance: In the muscular system, Chi3l1 protects skeletal muscle from TNFα-induced inflammation and insulin resistance via a protease-activated receptor 2 (PAR2)-dependent mechanism, and further study has shown that acute exercise contributes to an increase in Chi3l1 levels from 19.5 ± 1.1 ng/mL to 22.8 ± 1.2 ng/mL and to human myocyte proliferation [312,313].