IDO1 and breast cancer: Among other breast cancer signatures, seven signatures were found to be statistically different between patients with recurrence and without recurrence: CD8 T cells, cytotoxic cells, cytotoxicity, indoleamine 2,3-dioxygenase 1 (IDO1), interferon-gamma, programmed cell death protein 1 (PD1), and SRY-box transcription factor 2 (SOX2) (Figure 4A–G, Supplementary Table S2).