IFNA1 and rheumatoid arthritis: However, there are several reports of an IFN gene expression signature in RA peripheral blood [11, 12, 13, 14], and we recently identified a correlation between a type I ‘IFN‐high’ gene expression signature in peripheral blood neutrophils and good response to TNF‐i in a cohort of RA patients with severe disease activity [4, 15].