Researchers at the University of Florida’s Diabetes Institute have identified an early biological sign that signals the development of type 1 diabetes, according to a study published in the journal Diabetes.

The study found that the smallest collections of insulin-producing beta cells, as well as single cells scattered throughout the pancreas, are the first to die as the immune system launches its assault. This is thought to occur even before someone with diabetes exhibits symptoms.

The loss of these cells appears to be a harbinger of the next phase of Type 1 diabetes, when the immune system begins to destroy the larger and more significant collections of insulin-producing cells in the pancreas. These clusters of cells are called the islets of Langerhans.