IL33 and inflammation: Jaiswal and colleagues showed in 2020 that exposure to the fungal allergen Alternaria alternata promotes the accumulation of neutrophils in the airways and changes in pyruvate kinase isoenzyme M2 (PKM2) expression, which is associated with the release of both pro-inflammatory- (IL-6, IL-33, and TNF-⍺) and Th2-cytokines (IL-5 and IL-13) as well as acute airway inflammation [10].