Notably, human MMRd CRC patients who did not respond to anti-PD-1 treatment demonstrated an increased presence of myeloid cells expressing elevated levels of IL1B, TREM1, IL1RN, IDO1, IL6, TMEM176 and IFITM (Figure 3 E, Extended Figure 5), akin to our observations in the murine model. The gene discussed is IDO1; the disease is colorectal carcinoma.