GAD65 (524-543) acetate is a bioactive peptide, representing the amino acid sequence spanning the 524th to 543rd residues of glutamic acid decarboxylase 65 (GAD65). This compound is one of the initial segments found to induce proliferative T cell responses in the non-obese diabetic (NOD) mouse model of spontaneous autoimmune diabetes. It serves as a specific stimulator, potentially exhibiting low affinity for the spontaneously arising diabetogenic T cell clone BDC2.5. Immunization with GAD65 (524-543) acetate can increase the susceptibility of NOD mice to type 1 diabetes induced by the adoptive transfer of BDC2.5 T cells.