CTLA-4 blockade induces indoleamine 2, 3-dioxygenase where treatment with 1- methyl-d-tryptophan displays greater treatment effect in tumors with high ido expression. (March 2018) - Brown, Z.J.; Heinrich, B.; Ma, C.; Yu, S.J.; Zhang, Q.; Fu, Q.; Sandhu, M.; Agdashian, D.; Korangy, F.; Greten, T.F.