Nearly two decades ago, Sitkovsky et al. highlighted the various immunomodulatory effects of adenosine, primarily through activation of the adenosine A2 receptor (A2AR), and subsequently discovered that activation of the A2AR on antitumor T cells led to the inhibition of effector responses and contributed to tumor immune evasion [46, 47]. The gene discussed is ADORA2A; the disease is neoplasm.