**5. Role of fibrocytes in the pathogenesis of fibrotic disorders**

In contrast to acute inammatory reactions, which are characterized by rapidly resolving events; brosis typically results from chronic unsolved inammation or aberrant epithelial activation (King, Pardo & Selman, 2011). Despite having distinct etiological and clinical manifestations, fibrotic remodelling is characterized by fibroblast/myofibroblast activation, and excessive extracellular matrix accumulation leading to scarring formation and progressive dysfunction of a given organ.

Fibrocytes have become the focus of research of a wide variety of focal and diffuse fibrosing disorders in diverse organs including lung, heart, liver, and kidney (Barth et al., 2005; Sakai et al., 2006, 2008, 2010; Andersson-Sjöland et al., 2008; Scholten et al., 2011); primarily because of their ability to home into tissues and secret extracellular matrix components. More recently however, a large and varied amount of new knowledge about fibrocytes biology has emerged, rising new hypothesis that have enriched the understanding of these cells and their participation in fibrotic diseases.
