For example, Song et al.37 demonstrated that in a mouse model of osteoarthritis, the expression levels of CHI3L1 and MMP13 are positively correlated with inflammatory factors such as TNF-α, IL-1β, and IL-6, and can be suppressed by overexpression of nuclear factor erythroid 2-related factor 2 (Nrf2). Here, CHI3L1 is linked to osteoarthritis.