IFNG and arthritic joint disease: As might be expected, key pro-inflammatory cytokine USRs such as TNF, IFNG, IL6, and IL1B (Suhrbier, 2019) that were upregulated during CHIKV arthritis (Supplementary file 2i) were downregulated (negative z-scores) in the ameliorated foot swelling seen in Gzma-/- mice (Figure 2b, Supplementary file 2e).