We first compared the IFN-I score obtained with this NanoString-based protocol and the IFN-α2 levels measured by the Simoa technology across 196 samples collected from 119 pediatric patients with diverse clinical conditions (SLE = 22, DM = 7, mCTD = 9, monogenic type I interferonopathies [Aicardi-Goutières syndrome] = 4, other diseases = 77) and 7 HDs. Here, IFNA2 is linked to systemic lupus erythematosus.