Increased serum levels of Chi3l1 are also detected in patients with rhinitis, such as moderate/severe persistent allergic rhinitis (M/S PAR) and chronic rhinosinusitis with nasal polyps (CRSwNP), possibly contributing to remodeling the nasal mucosa, distinguishing CRSwNP endotypes, and predicting postoperative recurrence [63,64]. Here, CHI3L1 is linked to chronic rhinosinusitis with nasal polyps.