However, in our study, the expression levels of IDO1 were generally lower in high-risk group patients than in low-risk group patients (Figs. 3F and 4B and F), indicating that the role of IDO1 in the tumor microenvironment may be highly complex, potentially exerting different functions in various tumor microenvironments or among different patients. The gene discussed is IDO1; the disease is neoplasm.