Compared with normal tissue, CD244, B7-H4, BTLA, BTN2A1, BTN3A1, BTNL9, CD28, CD40, CD40LG, CD47, CD96, CD160, CD200, CEACAM1, DC-SIGN, LIGHT, SIRPA, PDL1, PDL2 and VISTA were down-regulated in breast cancer, whereas ADORA2A, B7-H3, CD70, CD80, CD86, CD137, CTLA-4, HVEM, IDO1, LAG-3, OX40, PD1 and TIGIT were up-regulated in breast cancer. The gene discussed is IDO1; the disease is breast cancer.