Fibrous tissue formation is one of the main elements of tissue repair and maintains the organ functional integrity after any aggression. When this connective tissue excessively accumulates, leading to tissue fibrosis, it induces serious impairment in the considered organ. The extracellular matrix--whose structure displays a great polymorphism--binds various active molecules (such as FGF, TGF beta, IFN gamma ...) and therefore locally regulates cellular activities. The latest studies both on fibrosis and on matrix receptors to cytokines have led to the idea of a matricial specificity to the cell's close surrounding.