IDO-positive tumors contained significantly higher amounts of FoxP3+ Tregs (p < 0.0001), IDO+ stromal immune cells (p < 0.0001), and both CD68+ and CD163+ tumor associated macrophages (TAMs) (p-values < 0.0001), compared to IDO-negative tumors (data not shown). The gene discussed is FOXP3; the disease is neoplasm.