IDO1 and neoplasm: Each CD44+ cell-type functions immunosuppression through different ways: CD44+ tumor cells express CD276, IL13, VEGFA, and IDO1; CD44+ TAMs express IL10, TGFB1, VEGFA, and HAVCR2; CD44+ T cells express CD274, TGFB1, CTLA4, LAG3, and PDCD1 (Figure 11C).