As expected, all 21 patients harbored antibodies to IFNα and IFNω (see Figure 2B), but when tested for IFNα and IFNω neutralization, the antibodies showed a striking segregation with clinical status (Figures 7C, 7D, and S7A): patients without T1D collectively neutralized all IFNα subtypes, whereas those with T1D showed only low or negligible neutralization. Here, IFNA17 is linked to type 1 diabetes mellitus.