Some cyclic dinucleotide (CDN) isoforms modify the course of type 1 diabetes (T1D) in non‐obese diabetic (NOD) mice. (a) Pre‐diabetic NOD female mice (n = 20, age 8 weeks) were treated with cdiGMP (150 µg/mouse) or saline two or three times per week (16× total from age 8‐14 weeks) and T1D onset was monitored. (b) As in (a), except that mice were treated with cGAMP (150 µg/mouse) or saline and monitored for T1D onset. Log‐rank test, *P < 0·05, NS, not significant. Data in panel (a) are representative of two independent experiments that yielded comparable outcomes.