AHR and asthma: In the context of asthma, AhR activation by TCDD or benzo[a]pyrene (B[a]P) can be pro-inflammatory and induce MUC5AC expression, leading to mucus hypersecretion, airway remodeling, dysregulation of antigen-presenting cells, and exacerbation of asthma (Wong et al., 2018; Poulain-Godefroy et al., 2020).