CLDN18 and gastric cancer: Briefly, examples include the use of biologics to target CLDN18.2 expression in gastric cancer to stimulate antibody dependent cytotoxicity, applying novel switch-control tyrosine kinase inhibitors in patients with GISTs with specific KIT exon mutations, the combination of pembrolizumab plus trastuzumab in HER2 overexpressed advanced gastric cancer, and the use of PARP inhibitors in pancreatic cancer patients with pathogenic variants BRCA and PALB2 [55,56,57,58,59,60].