Considering the optimal regimens for HER2-negative chemotherapy-naïve advanced gastric cancer patients with CPS < 5 tumors, the addition of anti-PD-1/PD-L1 antibody to chemotherapy may depend on a patient’s general condition, personal or institutional experience, approval status, adverse events (AEs), cost-effectiveness, and accessibility to subsequent immunotherapy. The gene discussed is ERBB2; the disease is gastric cancer.