Analysis of the RNA-seq data of monocytes derived from patients with polyarticular JIA (E-MTAB-14035) (Hounkpe et al, 2024) revealed the downregulated expression of ZNF334 and the oxidative protein folding enzyme PRDX4, along with upregulated expression of genes related to monocyte activation and pro-inflammatory cytokines (Appendix Fig. S2). The gene discussed is PRDX4; the disease is polyarticular juvenile idiopathic arthritis.