In a mouse transgenic model of breast cancer in which tumors were induced by expression of the oncogene Neu under the control of the mouse mammary tumor virus (MMTV) promoter, IDO inhibition with 1-methyl tryptophan (1-MT) was combined with paclitaxel, a chemotherapeutic agent commonly used to treat breast cancer [15]. This evidence concerns the gene IDO1 and breast carcinoma.