AHR-KYN activation has been confirmed in human brain tumors, melanoma, renal cancer, B-cell lymphoma, Ewing sarcoma, bladder carcinoma, cervix carcinoma, colorectal carcinoma, lung carcinoma, and ovarian carcinoma, and is associated with tumor progression and drug resistance [111]. Here, AHR is linked to B-cell non-Hodgkin lymphoma.