IFIT1 and mixed connective tissue disease: DNAm status at 10 CpGs sitting in genes PARP9, IFI44L, MX1, PLSCR1, IFIT1, NLRC5, and DDX60 show high diagnostic performance to distinguish MCTD from healthy patients (Area Under Curve (AUC) > 0.90), being the highest cg22930808 at PARP9 gene which exhibited an AUC of 0.94 (Figure 5A, Supplementary Table 12).