Previous studies have demonstrated that the smoking status is associated with elevated levels of CCL11 in young adults (Greisman et al., 2020) and that cigarette smoke can increase CCL11 expression and the number of eosinophils in nasal mucosae of young patients with perennial allergic rhinitis (Teixeira et al., 2018; Montaño-Velázquez et al., 2017). Here, CCL11 is linked to allergic rhinitis.