For example, genera like Clostridium induce the production of trimethylamine oxide, which triggers tumour cell apoptosis via PERK activation and boosts CD8+ T cell‐mediated anti‐tumour immunity in triple‐negative breast cancer in vivo (Wang, Rong, et al. 2022; Wang, Xu, et al. 2022). The gene discussed is CD8A; the disease is neoplasm.