The lungs have a large surface area and an epithelial lining that makes it more permeable to macromolecules than in any other source [26]. Negligible mucociliary mechanisms in the lungs further promote the uptake of insulin [27]. The motivation to explore this route was also because of the invention of nebulizers for asthma treatment, which highlighted many factors affecting this route of administration and how it can be used for insulin [28]. The gene discussed is INS; the disease is asthma.