The ILUSTRO trial is phase II non-randomized study assessing zolbetuximab efficacy (800 mg/m2 loading dose and then at 600 mg/m2 every 3 weeks thereafter) in patients with advanced/metastatic G/GEJ adenocarcinoma whose tumors have high (≥75% of tumor cells) or intermediate (≥50% but <75% expression of tumor cells) CLDN18.2 expression [46]. The gene discussed is CLDN18; the disease is gastroesophageal junction adenocarcinoma.