Hepatocellular carcinoma (HCC) is often associated with hepatitis B virus (HBV) infection. Cells of most HBV-related HCCs contain HBV DNA fragments that do not encode entire HBV antigens. We investigated whether these integrated HBV DNA fragments encode epitopes that are recognized by T cells and whether their presence in HCCs can be used to select HBV-specific T-cell receptors (TCRs) for immunotherapy.