One example of further differentiation of dermal fibroblasts is that upon injury, dermal fibroblasts can give rise to myofibroblasts, fibroblast cells with smooth muscle characteristics. Dermal cells differentiate into myofibroblasts by altering their actin gene expression (which is silenced in dermal fibroblasts).[1] When dermal fibroblasts express actin, the cells can slowly contract. This contraction plays a critical role in wound healing and fibrosis.