Type 1 diabetes (T1D) is caused by an autoimmune attack mediated by cytotoxic T cells. However as the attack unfolds, many other cell types participate–and some play an anti-inflammatory, regulatory, role. Interestingly, in the early stages of the disease, attacked islets often reside next to non-attacked islets. We hypothesized that the “tranquil” islets harbor elements which protect against the immune attack, and so ventured to compare attacked and non-attacked islets in pancreata at the pre-symptomatic stage of the disease. In this framework, we characterize the different cell populations which reside in either the attacked or non-attacked islet niche. Specifically, we focus on a population of macrophages with anti-inflammatory characteristics which reside exclusively in non-attacked islets. We now study the potential role of these cells in attenuating attack progression, and look for ways to activate them as means to delay–or even prevent–T1D.