MMP9 and dermatomyositis: Importantly, consistent with their migratory phenotype and mirroring findings from lesional CLE and DM in our scRNA-seq data, MMP9+CD14+ cells expressed high levels of CCR1 and showed slight upregulation of CCR5 and CCR2, the receptors for ligands including CCL2 and CCL8 (p<0.01) (Fig. 6I).