Galectin-1 derived from lung cancer is one of the culprits of DC cell incapacitation [141], and it has been demonstrated that this phenomenon is mediated by the galectin-1-CAF axis and mainly associated with the tryptophan 2,3-dioxygenase (TDO2)/kynurenine axis in CAFs [142]. Here, TDO2 is linked to lung cancer.