CD8A and type 1 diabetes mellitus: To identify the driving factors leading T1D progression to overt T1D, we implemented local and global sensitivity analyses using in silico data generated in our simulations and suggested the average lifespan of cytotoxic CD8+T-cells, initial number of apoptotic β-cells, number of binding sites on DCs for naïve CD8+ T cells, time interval of DCs movement in islets, and recruitment rate of DCs as five key drivers of T1D progression.