A new study published in International Archives of Allergy and Immunology investigated the expression of CC chemokineligand (CCL)21 and CCL25 in different types of chronic rhinosinusitis (CRS) and their significance in CRS development.This study enrolled 116 patients, wherefrom uncinate process mucosa or nasal polyp (NP) specimens were collected during surgery.Western blotting and immunohistochemistry were performed to detect the expression of CCL21 and CCL25, respectively, in the nasal mucosa. Cellular localization in NPs and their relationships with macrophages were determined.The findings showed that the expressions of CCL21 and CCL25 were increased in NPs only. These expressions were gradually increased in control—CRS without NP and CRS with NP groups—and were positively correlated with the disease severity. In addition, increased expressions of CCL21 and CCL25 in NPs were not related to eosinophil infiltration. Meanwhile, co-localization of CCL25+ cells and CD68+ macrophages was observed.CCL25 expression was increased in macrophage culture, especially in M1 macrophages,while CCL21 expression was not significantly associated with macrophages.Hence, it was concluded that CCL21 and CCL25 were significantly upregulated in NPs and positively correlated with disease severity. Furthermore, CCL25 upregulation was related to M1 macrophages.