KLRK1 and cancer: As shown in Fig. 5e-h, treatment with EHNA (30 μM) decreased the killing ability of NKG2D.CAR-NK-92 cells against all the testing CD73+ solid tumor cells (GBM43: *P < 0.05; GBM10: *P < 0.05; A549: **P < 0.01; PC3: **P < 0.01), further confirming the impairment of anti-cancer immunity by ADO.