IDO2 and pancreatic adenocarcinoma: Figure 5A shows the landscape of 22 subpopulations of immune cells in PAAD patients. Patients with high-GBP2 expression had a significantly higher proportion of active CD4 memory T cells, resting Dendritic cells, and M1 macrophages (Fig. 5B). Furthermore, the characteristic ICs, including PDCD1, PDCDL1, CTLA4, CD80, TIGIT, LAG3, IDO2, and VISTA, were more significantly expressed in the high-GBP2 expression group compared with the low-GBP2 expression group (Figs. 6A–6H).