C3 and diabetes mellitus: In order to challenge β-cells in vivo, these mice were then subjected to a multiple low-dose (MLD) streptozotocin model of diabetes induction, which produced a significantly more rapid blood glucose elevation in flox/RIP-Cre β-cell-specific C3 knockout mice, as compared to floxed littermate controls (Fig. 7C), indicative of enhanced β-cell death and loss of insulin production.