FOXP3 and neoplasm: IDO1 inhibition has been demonstrated to increase conversion of Foxp3+ Tregs to Th17-like cells in tumor-draining lymph nodes in mice bearing B16-F10 tumors.42 However, when treating mice with epacadostat, we did not detect any significant differences in effector T-cells or T-regulatory cells in the lymph node, and instead the major effects of epacadostat therapy on immune cell phenotypes was observed within the tumor microenvironment.