The ILUSTRO study (NCT03505320) is currently evaluating the efficacy and safety of targeting CLDN18.2 with zolbetuximab plus targeting PD-1 with nivolumab in combination with chemotherapy as first-line treatment for patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or mG/GEJ adenocarcinoma. This evidence concerns the gene ERBB2 and gastroesophageal junction adenocarcinoma.