Over expression of indoleamine 2,3-dioxygenase(IDO)is an important mechanism that is responsible for immune tolerance of tumor.

• 吲哚胺2,3-二加氧酶(idoleamine2,3-dioxy-genase,IDO)的高表达是导致肿瘤免疫耐受的一个重要机制。 诱导IDO的表达具有两种信号传导途径。