Figure 3. SPARC induces proliferation of HTF cells. For quantification of cell proliferation, HTF were incubated with indicated concentrations of SPARC (A) and/or 200 pg/ml TGF-β1 (B) in BrdU containing (10 µM) serum free cell culture medium. After three days, incorporated BrdU level were measured by ELISA technique and expressed as relative absorbance to untreated controls (mean±SEM of 2 independent experiments; n≥24; *p<0.01; **p<0.001).