Proinflammatory cytokines such as interferon-gamma (IFN)-γ, tumor necrosis factor-alpha (TNF-α) and interleukin 1-beta (IL-1β) and reactive molecules such as nitric oxide (NO) and various related free-radical and oxidant species produced by infiltrated immune cells are major mediators of the induction of apoptosis, the main form of cell death observed through biopsies of islets of rats and humans with T1D (37). Here, IFNG is linked to type 1 diabetes mellitus.