With respect to inflammatory diseases associated with the skeletal system, combined therapy with tocilizumab (TCZ) and methotrexate (MTX) can result in a significant increase in body mass index (BMI), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels, and a significant decrease in the TC/HDL-C ratio and Chi3l1 levels in RA patients [307]. Here, CHI3L1 is linked to rheumatoid arthritis.