Surgery remains a mainstay in the treatment of many forms of cancer, but it is no longer used in diagnosis due to the risks associated with surgery and improved nonsurgical diagnostic methods.

Insulin is a peptide therapeutic used to manage type 1 diabetes, which affects more than 20 million people worldwide according to the international diabetes federation. a significant limitation to the broad distribution and use of insulin to treat type 1 diabetes is the fact that it must be administered by injection rather than orally. why is insulin administered by injection and not orally?