In a multicentric cohort of 338 patients with NSCLC, baseline fecal A. muciniphila was associated with a better overall response rate (ORR: 28% vs. 18%, p = 0.04) and longer overall survival (OS) (18.8 months vs. 15.4 months, p = 0.03), independently of PD-L1 tumor proportion score (TPS), Eastern Cooperative Oncology Group Performance Status (ECOG-PS), or antibiotics therapy. The gene discussed is CD274; the disease is non-small cell lung carcinoma.