A plant expressing a cytokine and an autoantigen is disclosed. An example of a cytokine is a contra-inflammatory cytokine, for example IL-4 and IL-10, and an example of autoantigen is GAD. A novel method for the production of transgenic proteins of interest suitable for oral administration is also disclosed. Further, non-food crop plants expressing one or more proteins of interest are disclosed, as is a method involving the preparation of a protein of interest suitable for oral administration within a non-food crop plant comprising, transforming the non-food crop plant with a suitable vector containing a gene of interest and appropriate regulatory regions to ensure expression of the gene of interest within the non-food crop plant, such that the non-food crop plant is characterized as being non-toxic, non-addictive, palatable, and requiring minimal or no processing prior to oral administration. An example of a non-food crop plant is low alkaloid tobacco. Proteins of interest may include pharmaceutically active proteins such as growth regulators, insulin, interferons, interleukins, growth hormone, erythropoietin, G-CSF, GM-CSF, hPG-CSF, M-CSF, Factor VIII, Factor IX, tPA, antibodies, antigens and combinations and/or derivatives thereof.