The reduced abundance of Bacteroides thetaiotaomicron in recurrent HCC patients was linked to diminished acetic acid-mediated polarization of M1 macrophages and CD8+ T-cell activation, with mechanistic studies showing that this effect involves histone acetylation-dependent upregulation of ACC1 and is critical for maintaining an antitumor immune microenvironment [74]. The gene discussed is CD8A; the disease is hepatocellular carcinoma.