The blood transcriptome of untreated JIA patients displayed elevated IL-1β and IL-6 bioactivity (Figure 2A) (Brachat et al., 2017), but this was not consistently evident in several RA blood transcriptome datasets (Figure S1) (Lee et al., 2020; Macías-Segura et al., 2018; Tasaki et al., 2018). Here, IL1B is linked to rheumatoid arthritis.