Type 1 diabetes (T1D) is characterised by immune-mediated pancreatic islet β-cell destruction. The initial immune response engenders secondary and tertiary responses which collectively result in impairment of β-cell function, progressive destruction of β-cells and consequent development of T1D. The process is insidious and may evolve over many years, with the overt expression of clinical symptoms becoming apparent only when most β-cells have been destroyed. Over the last quarter century much investigation has been directed at interdicting the T1D disease process, both during the stage of evolution of the disease and at the time of disease onset. This chapter of the Yearbook of Advanced Technology and Treatments in Diabetes reviews the key articles that have appeared in this field between January 2008 and June 2009.