S100A9 and systemic sclerosis: Patients with SSc exhibited altered expression of proteins involved in various biological processes, including extracellular matrix formation and cell-to-cell adhesion (elevated Calpain, EphA5, IDS, MATN2, MMP-12, TNR4, and reduced levels of desmoglein-1, SNP25), angiogenesis (increased levels of anti-angiogenic factors such as Ang2 and high molecular weight kininogen), lymphocyte recruitment, activation, and signaling (elevated levels of CXCL-1, LAG3 and decreased levels of SH21A), and overall inhibition of neutrophil function (decreased levels of G-CSF-R, CD177, calgranulin B; Figure 1).