CD8A and hepatocellular carcinoma: In conclusion, the gut microbiota intricately shapes both innate and adaptive immune responses in HCC by influencing key immune cell populations, such as Tregs, MDSCs, CD8+ T cells, and DCs, and increasing evidence suggests that modulating the microbiome through strategies such as fecal microbiota transplantation, probiotics, antibiotics, dietary interventions, or nanodelivery systems may help control HCC development and improve clinical outcomes, such as by enhancing the efficacy of ICIs [85, 86].