CD8A and neoplasm: Actinomyces are part of the healthy core microbiota (Kononen & Wade, 2015); however, in patients with sporadic early-onset colorectal cancer, the co-presence of this genus with several pro-tumor microbial taxa promotes inflammation through activation of the toll-like receptor (TLR)2/NF-κB and TLR4/NF-κB signaling pathways, and also impair the anti-tumor immune responses by reducing the accumulation of CD8+ T lymphocytes (Xu et al., 2022).