First of all, there is no universally accepted combination of genes to be analysed for the calculation of the IFN score, which is classically assessed by the expression level of different IFN- induced mRNA.17,19 In the most recent literature, four or five gene sets19,21 have been used when evaluating the IFN signature in autoimmune rheumatic diseases (ARDs). This evidence concerns the gene IFNA1 and acute respiratory distress syndrome.