The presence of an immunological tumor center, which includes tumor-reactive chemokine ligand 13 (CXCL13) T cells, epithelial interferon-stimulated gene programs, and early immune remodelling characterized by enhanced infiltration of CD8+ T cells, is responsible for the clinical response to first-line chemoimmunotherapy for advanced GC [31]. The gene discussed is CD8A; the disease is gastric cancer.