AHR and colonic neoplasm: Previous work in our lab revealed that AHR and its tryptophan-derived ligand, Kyn, play an important role in colonic cell growth, and thus AHR acts as a central integrator of growth signaling in colon cancer (Lafita-Navarro et al., 2018; Perez-Castro et al., 2021; Venkateswaran et al., 2019b).