The article by Kalluri and Neilson reviews the role of epithelial-mesenchymal transition (EMT) in fibrosis, particularly in kidney disease. EMT is a dynamic process where epithelial cells lose their polarized structure and gain motility, leading to the formation of fibroblasts. This process is regulated by various cytokines and growth factors, such as TGF-β, EGF, and FGF-2, which induce the expression of key proteins like β-catenin and Snail. The authors highlight that EMT is not just a developmental process but also plays a crucial role in adult tissue repair and fibrosis. They discuss the mechanisms of EMT, including the involvement of GTPases, transcription factors, and signaling pathways. The review also emphasizes the importance of EMT in the progression of kidney fibrosis, where a significant proportion of fibroblasts originate from tubular epithelial cells. The use of BMP-7 as a therapeutic agent to reverse EMT and fibrosis is discussed, along with the potential for EMT to be a therapeutic target in fibrotic diseases.The article by Kalluri and Neilson reviews the role of epithelial-mesenchymal transition (EMT) in fibrosis, particularly in kidney disease. EMT is a dynamic process where epithelial cells lose their polarized structure and gain motility, leading to the formation of fibroblasts. This process is regulated by various cytokines and growth factors, such as TGF-β, EGF, and FGF-2, which induce the expression of key proteins like β-catenin and Snail. The authors highlight that EMT is not just a developmental process but also plays a crucial role in adult tissue repair and fibrosis. They discuss the mechanisms of EMT, including the involvement of GTPases, transcription factors, and signaling pathways. The review also emphasizes the importance of EMT in the progression of kidney fibrosis, where a significant proportion of fibroblasts originate from tubular epithelial cells. The use of BMP-7 as a therapeutic agent to reverse EMT and fibrosis is discussed, along with the potential for EMT to be a therapeutic target in fibrotic diseases.