Transdifferentiation comes of age

Abstract

Five years ago we wrote an editorial in this journal about the possible transdifferentiation of tubular epithelial cells to fibroblasts [1]. We had just cloned a fibroblast specific protein (FSP)‐1 in murine kidney fibroblasts and had described that de novo expression of this protein could be detected in selected tubular epithelial cells during late stages of renal fibrogenesis, indicating possible epithelial–mesenchymal transformation (EMT) or transdifferentiation [2]. After this passage of time, we would like to readdress the issue of transdifferentiation and the scientific evidence collected in the meantime supporting its existence.