In this review, we primarily focus on phenotype and development of hepatic TRM cells, mainly CD8+ TRM cells, with emphasis on their protective roles in viral and parasite infection, non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC) and liver transplantation, as well as their pathogenic roles in autoimmune liver diseases (AILD) (Table 1). This evidence concerns the gene CD8A and hepatocellular carcinoma.