AHR and carcinoma: Regardless of whether the AhR agonists contained in ingested coffee stay in the gastrointestinal tract or enter the systemic circulation, it should be kept in mind that there is a limitation in our study which precludes generalization: although coffee stimulated AhR in HepG2, Caco-2, and MCF-7 cells, they are immortal carcinoma cell lines maintained exvivo in the laboratory conditions.