A preparation of T lymphocytes harvested from a patient with cancer and transduced with the PG13/Lnc8 retroviral vector, a clone of the LN vector that encodes the neomycin phosphotransferase gene. The modified T lymphocytes are cloned using an ex vivo technique and infused back into the patient, where they may elicit a host immune response against tumor cells. The neomycin phosphotransferase gene product has no direct therapeutic value; it serves as a molecular marker to monitor the presence and localization of the PG13/Lnc8-transduced T-lymphocytes in the host. (NCI04) [ ]