GAD2 and type 1 diabetes mellitus: All SPS patients with high (> 10,000) anti-GAD65 serum titers also had high CSF titers, from 92 to 2500 ng/mL, and specifically immunoreacted with GABA-ergic neurons on rat cerebellum (Fig. 2A–C) and recognized recombinant GAD65 (Fig. 3) [18]; in contrast, the controlled patients with insulin-dependent diabetes had low serum anti-GAD65 antibody titers and no reactivity to recombinant GAD65 (Fig. 3).