Increase Support for Life-saving Endocrine Transplantation Act or the ISLET Act This bill removes pancreatic islets that are donated from human cadavers from regulation as a drug or biological product by the Food and Drug Administration (FDA). (Islets are groups of cells, including those that make insulin, in the pancreas, and islet transplantation is an experimental treatment for certain conditions, such as type 1 diabetes.) Current FDA guidance treats pancreatic islets as a biological product, which makes them subject to the biological license application process and related standards for manufacturing practices, safety, identity, purity, and potency. The bill, instead, treats human cadaveric islets as organs, which makes them subject to the regulatory framework that governs the allocation, safety, and efficacy of organ donation and transplantation. That framework, developed by the Health Resources and Services Administration, is carried out by contract through the Organ Procurement and Transplantation Network. (The network is a public-private partnership that links the professionals involved in the U.S. donation and transplantation system.) Specifically, the bill defines human cadaveric islets as organs and excludes them from definitions related to the regulation of drugs and biological products.