Progression to type-1 diabetes is characterised by chronic inflammation and a loss of function of islet β cells (shown in pale orange). This reduces the proliferation of these cells and often leads to a form of programmed cell death called apoptosis (bottom left). Fu et al. reveal that I-BET151 works to resolve inflammation of the islet β cells (insulitis) mainly by two mechanisms. Firstly, it encourages macrophages in the pancreas to convert from being pro-inflammatory (which release cytokines that promote inflammation, top left) to being anti-inflammatory type (top right). This inhibits the further recruitment of T cells and dampens inflammation. Secondly, I-BET151 enhances the proliferation of islet β cells and enhances insulin production (bottom right).