IGFBP5 influences the expression of genes involved in fibrogenesis. LX2 cells were transfected with small interfering control (siCtrl) or IGFBP5 siRNA (siBP5). Sixteen hours after transfection, medium was replaced by serum-free medium. Recombinant IGFBP5 (rIGFBP5) was added at 24 h and 45 h, after replacing the medium, to siIGFBP5 transfected cells (siBP5+rBP5). After 48 h of culturing on serum-free medium RNA was isolated from control, transfected and transfected treated with rIGFBP5. For comparison, RNA was isolated from LX2 cells overexpressing IGFBP5 cultured in serum-free medium (LX2(BP5)). Collagen 1α1 (A),TIMP1 (B) and MMP1 (C) mRNA levels were measured with quantitative polymerase chain reaction, normalized to 36B4 and given as a percentage of control cells.