Specifically, cisplatin-resistant lung cancer cells were reported to exhibit increased consumption of extracellular tryptophan in comparison to parental lung cancer cells, and increased extracellular uptake of tryptophan was met with increased IDO1 activity through Kyn-mediated activation of the Aryl hydrocarbon Receptor (AHR) (30). The gene discussed is AHR; the disease is lung carcinoma.