FN1 and renal fibrosis: Gene therapy using DKK1 significantly suppresses fibroblast-specific protein 1(fsp1), a marker for fibroblasts and myofibroblasts, type I collagen, and fibronectin mRNA in the model of obstructive nephropathy, thereby repressing the activation of myofibroblast and improving renal fibrosis (He et al., 2009).