IL17A and type 1 diabetes mellitus: Pharmacological inhibition of the IL-12/23 pathway in a small cohort of adults with new-onset type 1 diabetes reduced IL-17A-producing T cells, supporting a pathogenic role for this pathway.13, 15 In a randomised, placebo-controlled trial in new-onset type 1 diabetes, inhibition of IL-12/23 preserved C-peptide, and mechanistic analyses implicated that the IL-17 pathway was involved.9