ADORA2A and cancer: According to Michail Sitkovsky[147], the observed tumor regressions in patients with RCC, who were previously untreatable and refractory to PD-1 blockade, likely occurred in patients meeting specific criteria: their tumors were immunogenic, developed tumor-reactive effector T cells, retained a significant number of effector cells post-toxic cancer chemotherapies, and were protected by immunosuppressive extracellular ADO to A2AR signaling.