Moreover, COX-2 was correlated with anti-CTLA4 response and a group of gastric cancer patients with high COX-2 levels showed lower sensitivity to afatinib, erlotinib, gefitinib, ibrutinib, osimertinib, Wnt-C59, AZD1332, AZD3795, CDK9, P22077 and XAV939 (117). Here, PTGS2 is linked to gastric cancer.