STAT1 and type 1 diabetes mellitus: Indeed, type I IFN has been detected directly within the islets of subjects with T1D [6], and a range of downstream ISGs, such as signal transducer and activator of transcription 1 (STAT1), IRF1, HLA-E and myxoma resistance protein 1 (Mx1, also known as MXA) are also elevated at both the RNA and protein level in T1D islets [74,75,76].