PTPRN and type 1 diabetes mellitus: We analyzed the following: (a) insulin secretion, (b) insulin sensitivity, and (c) pro-inflammatory interleukin-17 (IL-17) levels in peripheral blood in 17 healthy first-degree relatives in stage 1 (FDRs1) (GAD+, IA2+), 34 FDRs in stage 0 (FDRs0) (GAD−, IA2A−), 24 recent-onset T1D (R-T1D) patients in the insulin-requiring state (IRS), 10 in clinical remission (CR), and 18 healthy unrelated controls (HC).