CD274 and diabetes mellitus: Injection of pCI/ppins1–89, but not pCI/ppins1–36 or pCI/ppins15–66 vaccines suppressed diabetes development after an injection (at d12 post vaccination) of the diabetogenic pCI/ppins into PD-L1−/− mice (Fig. 7b–d), indicating that the Treg-stimulating domain is localized around ppins67–89.