ACTA1 and systemic sclerosis: Of note, concerning systemic involvement in HOCl-SSc, iNOS−/−-MSC were not able to reduce fibrotic markers such as collagen 1 and α-SMA and inflammatory cytokines (IL-1β and IL-6) in lung tissue, while WT-MSC had a positive impact on pulmonary fibrosis in this model (data not shown).