ADO and neoplasm: Overall, the multifaceted role of ADO in tumor immune evasion is seen in its promotion of pro-tumor rather than antitumor immune responses, dictation of Treg function, inhibition of effector T cells, modulation of anti-inflammatory cytokines, and induction of immune checkpoints as illustrated in Figure 1 (83, 84, 86, 88, 89, 94).