text: Closely tied with the field of biotechnology, this subject of cell engineering employs recombinant DNA methods to induce cells to construct a desired product such as a protein, antibody, or enzyme. One of the most notable examples of this subset of cellular engineering is the transformation of E. Coli to transcript and translate a precursor to insulin which drastically reduced the cost of production. Similar research was conducted shortly after in 1979 in which E. Coli was transformed to express human growth hormone for use in treatment of pituitary dwarfism. Finally, much progress has been made in engineering cells to produce antigens for the purpose of creating vaccines.