CD63 and allergic rhinitis: We assessed omalizumab's impact on basophil reactivity and its clinical associations in moderate-to-severe AR.<h4>Objective</h4>This study aimed to determine the predictive value of CD203c and CD63 as basophil activation markers for clinical response to omalizumab in patients with moderate-to-severe allergic rhinitis.<h4>Methods</h4>We collected and analyzed clinical symptoms and the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores of 27 patients with moderate-to-severe AR who were treated with omalizumab for more than 12 weeks.