IFNA1 and rheumatoid arthritis: In addition, blood-based gene expression examination showed that radiographic severity monitored by erosion assessment in RA patients was associated with upregulation of IFN- and TGFβ-signaling and apoptosis activity, and with downregulation of oxidative phosphorylation and mitochondrial function both at baseline and after three years of the disease.90 Another study identified a set of 14 genes including proinflammatory and growth arrest-related genes that predict severity of the disease that were upregulated in peripheral blood.91