CXCL10 and asthma: For omalizumab, our finding that higher levels of CXCL10 was associated with better response is consistent with prior studies that have shown that elevated CXCL10 is associated with omalizumab response and/or promotes allergic airway inflammation.43–45 Elevated CXCL10 might reflect a group of patients who meet eligibility criteria for omalizumab and whose asthma is predominantly triggered by environmental allergens, as opposed to patients who may have perennial rhinitis but whose asthma is primarily triggered by other agents like smoke10,44.