IDO1 and breast cancer: Interestingly, low-risk patients with altered FGFR3 had a lower expression of immune checkpoint genes, including PD-L1, CTLA4, TIM3, LAG3, PD-1, CD27, CD47, and IDO1 (p < 0.05); on the contrary, high-risk patients with altered FGFR3 had a higher expression of TIM3 and CD47 (p < 0.05), whereas the expression level of PD-L1 in BC patients with altered FGFR3 was quite low (Figure 10F).