A method of generating genetically modified cells, wherein the genetically modified cells are selected from T cell receptor T cells (T-TCR), chimeric antigen receptor T cells (T-CAR) and cytokine induced killer cells expressing one or more T cell receptors (CIK-TCR) or chimeric antigen receptors (CIK-CAR), the method comprising: (a) non-viral transfer of one or more exogenous nucleic acids encoding antigen receptors, T cell receptors, chimeric antigen receptors, suicide genes or genes encoding an inducible Caspase 9 system, or combinations thereof into a population of mononuclear cells in a cell culture ; (b) addition of one or more differentiating agents to the cell culture after the transfer of nucleic acids, wherein the differentiating agents differentiate the mononuclear cells in the cell culture into T cells and/or cytokine induced killer cells; (c) addition of antigen presenting cells to the cell culture within 5 days after the transfer of nucleic acids; (d) addition of one or more stimulating agents to the cell culture within 5 days after the transfer of nucleic acids; optionally step (e), addition of one or more stimulating and expanding agents to the cell culture after the transfer of nucleic acids; and optionally step (f) isolating the cells from the cell culture to obtain a cell population comprising the modified cells; wherein: - said stimulating agent is selected from: CD3+ cells; anti-CD3 antibodies; OKT3; anti-CD28 antibodies; anti-TCR antibodies; CD3/CD28; PHA, PMA and ionomycin; anti-TCR-loaded artificial antigen presenting cells; irradiated OKT3-loaded K562-derived artificial antigen presenting cells; - said differentiating agents comprise cytokines, IFN-γ, IL-4, IFN-α, IL-10, IL-12, IL-6, IL-21, IL-23, IL-Iβ, TGF-β or combinations thereof; - said stimulating and expanding agents comprise cytokines, IL-2, IL-7, IL15, IL-21 or combinations thereof. (a) non-viral transfer of one or more exogenous nucleic acids encoding antigen receptors, T cell receptors, chimeric antigen receptors, suicide genes or genes encoding an inducible Caspase 9 system, or combinations thereof into a population of mononuclear cells in a cell culture ; (b) addition of one or more differentiating agents to the cell culture after the transfer of nucleic acids, wherein the differentiating agents differentiate the mononuclear cells in the cell culture into T cells and/or cytokine induced killer cells; (c) addition of antigen presenting cells to the cell culture within 5 days after the transfer of nucleic acids; (d) addition of one or more stimulating agents to the cell culture within 5 days after the transfer of nucleic acids; - said stimulating agent is selected from: CD3+ cells; anti-CD3 antibodies; OKT3; anti-CD28 antibodies; anti-TCR antibodies; CD3/CD28; PHA, PMA and ionomycin; anti-TCR-loaded artificial antigen presenting cells; irradiated OKT3-loaded K562-derived artificial antigen presenting cells; - said differentiating agents comprise cytokines, IFN-γ, IL-4, IFN-α, IL-10, IL-12, IL-6, IL-21, IL-23, IL-Iβ, TGF-β or combinations thereof; - said stimulating and expanding agents comprise cytokines, IL-2, IL-7, IL15, IL-21 or combinations thereof. <EOS>