Furthermore, the tryptophan 2,3-dioxygenase (TDO2) and indoleamine-2,3-dioxygenase (IDO) released by α-SMA+ CAFs isolated from lung cancer enhance tryptophan degradation in kynurenines (Kyn) and consequently inhibits DCs differentiation and functions [8]. The gene discussed is TDO2; the disease is lung cancer.