For example, while PD-1hi CD8+ Trm cells highly express cell adhesion and tissue positioning markers, including CD69 and integrins CD11c, CD49a, CD49b, and CD103 in HCC (87), CD103+CD8+ Trm cells express tissue residency-promoting molecules, such as CD69, CD49a, and RUNX3, in gastric cancer (9). This evidence concerns the gene CD69 and hepatocellular carcinoma.