The observed upregulation of hormone processing enzymes (PCSK1 and CPE) and proteins mediating insulin secretion (PPP1R1A) in the AAb+ pre-T1D stage is particularly interesting since altered β-cell prohormone processing and secretion has been increasingly recognized as an early and persistent finding in T1D [50]. This evidence concerns the gene PPP1R1A and type 1 diabetes mellitus.