TNF and asthma: Candidate genes for asthma include interleukin (IL)-4, IL-13 and IL-4R, ADRB2, MS4A2, tumor necrosis factor α (TNFα), cluster of differentiation (CD)14, human leukocyte antigen (HLA)-DRB1 and HLA-DQB1 (Toskala and Kennedy, 2015; Willis-Owen et al., 2018).