RB1 and diabetes mellitus: Neutralization of RyR2 activity was significantly decreased in diabetes (0.44 ± 0.04, P < 0.01), insulin (0.65 ± 0.03, P < 0.01), and Rb1 (0.61 ± 0.03, P < 0.01) groups from the control group (0.89 ± 0.06); insulin group (P < 0.05) and Rb1 group (P < 0.05) were significantly increased from the control group (Fig. 8A).