Furthermore, miR-1246 and miR-1290 are overexpressed in PC-derived exosomes, and miR-1290 enhances the expression of ACTA2 and fibrosis-related genes in PSCs.44 These findings demonstrate that exosomes secreted by PC cells or PSCs play a unifying role in the pathogenesis and microenvironment of PC (Fig. 3). This evidence concerns the gene ACTA2 and pachyonychia congenita.