Notably, BAY-218 enhanced therapeutic efficacy of PD-L1 blockade in the CT26 model.205 This compound also recently entered a Phase 1 clinical trial in patients with advanced cancer.207 Although initial preclinical results look promising, only clinical trials will show how well AHR inhibitors are tolerated, whether they effectively inhibit tumour progression, and in which cancer entities they are effective. Here, AHR is linked to neoplasm.