In addition, symptoms brought by AR such as apnea and snoring were also considered to be risk factors for sleep-disordered breathing events and contributed to the development of OSA.[61] In addition, some studies had demonstrated that several chemical mediators and inflammatory cytokines play interaction roles between AR and OSA, including histamine, cysteinyl leukotrienes (cysLTs), interleukin-1β(IL-1β), and interleukin-1 (IL-4) and so on.[58,62] Given the impact of AR to OSA, it seemed logical to investigate their relationship which may help understand overlapped subjects.[62]. This evidence concerns the gene IL4 and obstructive sleep apnea syndrome.