ADORA2B and gastric cancer: Adora2b-specific inhibitor: PSB-603 (IC50=1.13 nM) competitively inhibits Adora2b, reducing tumor volume in MKN-45 nude mice by 64% and decreasing lung metastasis rates from 62% to 18% (p<0.01) (26)。PSB-603 (Adora2b-specific antagonist, IC50=1.13 nM) combined with cisplatin achieved an objective response rate (ORR) of 29% in advanced gastric cancer, significantly higher than cisplatin monotherapy (14%, p<0.05) (26).