1. exp epitope/2. epitope*.mp3. 1 or 24. exp HLA antigen/5. exp CD8 antigen/6. 4 or 57. exp Hepatitis B/8. (Hepatitis B or HBV).mp.9. 7 or 810. 3 and 6 and 9. This evidence concerns the gene CD8A and hepatitis B virus infection.