The potential mechanism by which A. muciniphila and E. hirae influence anti‐PD‐1 efficacy may be associated with the aggregation of central memory T cells and stimulation of IL‐12 secretion in mesenteric lymph nodes, lymph nodes in tumor drainage areas, and tumor beds of mice receiving transplants of ineffective patient colonies.97 The gene discussed is PDCD1; the disease is neoplasm.