Much ado about TDO

While companies are pursuing indolamine 2,3-dioxygenase inhibitors for cancer, German academics have identified an alternate tryptophan metabolism pathway mediated by an enzyme called tryptophan 2,3-dioxygenase that tumors exploit to grow and evade the immune system.¹ The study suggests the need to monitor tumors for activation in both pathways.

Indolamine 2,3-dioxygenase (IDO)-mediated tryptophan catabolism generates kynurenine, a metabolite that inhibits the antitumor immune response.²...