A therapeutic agent and method of administering the therapeutic agent for the treatment of tumors and/or cancers of a subject, the therapeutic agent comprising a first pharmaceutical composition comprising a first active ingredient in a first druggable vehicle, wherein the first active ingredient comprises a nucleic acid encoding a labelling polypeptide comprising one or more antigenic epitope peptides and/or encoding a MHC protein; a second pharmaceutical composition comprising a second active ingredient in a second druggable vehicle, wherein the second active ingredient comprises immune cells purified from peripheral blood or from tumor tissue and are cultured in vitro; wherein the nucleic acid when administered to the subject as part of the pharmaceutical composition causes the tumor cells and/or cancer cells of the subject to express the one or more antigenic epitope peptides to elicit an immune response of the immune cells.