The metabolism of tryptophan through the kynurenine pathway is particularly important in the context of cancer. Enzymes such as indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) convert tryptophan into kynurenine. Elevated levels of these enzymes in tumors can deplete tryptophan in the local environment, leading to immune suppression and allowing cancer cells to evade immune detection.
