The AHR (aryl hydrocarbon receptor)–ligand-dependent transcription factor regulates gene expression in lipid and cholesterol synthesis, xenobiotic (e.g., aryl hydrocarbons) metabolism, and many cellular responses not only in different physiological cells but also in all stages of cancer development (it can act as a tumor suppressor or tumor promoter) [92]. The gene discussed is AHR; the disease is neoplasm.