Pathway analysis and gene expression profiling of ANCA-negative VM muscle biopsies exhibited a marked upregulation of interferon-gamma (IFNγ)-inducible genes, with expression levels similar in magnitude (but different in nature) to those observed in dermatomyositis (DM) (Figs. 6, 7, Supplementary Fig. S4, Supplementary Fig. S5). Here, IFNG is linked to dermatomyositis.