For diseases that require occasional administration of therapeutic proteins, this may be acceptable to patients, but for chronic diseases such as diabetes that require frequent administration of insulin, the pain of injections leads to poor adherence to treatment, suboptimal therapy and increased hospitalization/morbidity.4 A study by Morris et al. found that around 28% of population with Type 1 diabetes mellitus did not adhere to prescribed insulin injection dose.5 Oral delivery has the potential to address this limitation. This evidence concerns the gene INS and type 1 diabetes mellitus.