IL4 and sleep disorder: Given that tumor necrosis factor-α (TNF-α) [33], hsCRP[34], inflammatory cytokines (IL2, IL4, IL6) [35] and lipid peroxidation [36] are increased in OSAS patients, we further analyzed whether immune and inflammatory factors, including fever, leukocyte count, lymphocyte count, hsCRP and PCT, were associated with the incidence of sleep disorders in our COVID-19 cohort, and found a negative association between them.