CD8A and hepatocellular carcinoma: However, another study revealed that a distinct gut microbiome marked by increased short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides and Veillonella, in MASLD-HCC patients was associated with elevated serum and fecal butyrate levels, which in turn promoted an immunosuppressive environment by expanding IL-10+ Tregs and reducing cytotoxic CD8+ T-cell function, highlighting the antagonistic effects of gut-derived butyrate on HCC progression [80].