The MAF was found to be the lowest for IFNA rs3758236 A allele in MCTD patients (A: 0.11) and for IFN-B rs7873167 G allele in MCTD patients and controls (G: 0.11); while the highest was for IFN-G rs2069705 G allele in the controls (G: 0.52) (Table S3 in Supplementary Files). This evidence concerns the gene IFNA1 and mixed connective tissue disease.