Schematic model of myofibroblast differentiation in the skin. The local myofibroblasts characteristic for α-SMA expression are originated from multiple cell sources in the skin and nominated from at least 3 distinct cell sources: BM-derived mesenchymal stem cells, microvascular pericytes, and resident fibroblasts in the donor skin graft and/or in the perilesional host skin. Some molecules can organise the cell-type-specific differentiation into dermal myofibroblasts.