CHI3L1 and osteomyelitis: Chi3l1 can aggravate S. aureus-induced osteomyelitis by mediating osteoblast differentiation and proliferation through the activation of the p38/MAPK and Smad pathways, whereas the inhibition of Chi3l1 contributes to reducing the debilitating effects of S. aureus in this disease (Figure 2) [270,271].