AHR and neoplasm: AhR is a multifunctional regulatory protein that senses and responds to polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene, BaP) and persistent planar halogenated polycyclic hydrocarbons (e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) as well as a ligand-activated transcription factor that facilitates tumor progression and disease tolerance[13].