HSP47 was found mainly expressed in the α-SMA-positive cells (Fig. 2), i.e. myofibroblasts (Abraham et al., 2009) and the number of HSP47-positive cells determined by IHC in the present study was also increased in the skin tissues from SSc patients, suggesting a potential role of HSP47 in the development of SSc fibrosis. Here, ACTA1 is linked to systemic sclerosis.