IL4R and chronic rhinosinusitis with nasal polyps: While no currently available drugs block 15LO1 activity in humans, a loss-of-function mutation of ALOX15 confers strong protection against the development of CRSwNP in cohorts from Sweden and the United Kingdom (25), strongly suggesting a key role for 15LO1 and its products in IL-4Rα–driven epithelial functional changes, and potential for therapeutic targeting of 15LO1 with inhibitors.