IFNA1 and rheumatoid arthritis: This clustering separated the samples into two main groups, one of patients with RA (n = 26/102, 25.5%) with high expression (Figure 2, blue dendrogram) of this set of IFN-related genes (IFNhigh) and another (n = 76/102, 74.5%) with lower expression (Figure 2, purple dendrogram) (IFNlow).