In contrast, clinical trials of IL-33/ST2 axis therapies (itepeximab, astegolimab, tozoracimab) in asthma and COPD have reported predominantly mild to moderate events such as nasopharyngitis, upper respiratory tract infections, and headache, with low rates of serious treatment-related adverse events [118–120]. This evidence concerns the gene IL1RL1 and Recurrent upper respiratory tract infections.