TNF and asthma: Other potential serum biomarkers are cytokines, chemokines, and specific molecules, which are elevated in T2-low asthma, such as IL-1β, IL-6, IL-8, IL-17, brain-derived neutrophilic factor (BDNF), S100A9, folliculin (secreted in case of epithelial damage), myeloperoxidase, neutrophil elastase, and tumor necrosis factor (TNF)α [31,64,67].