Figure 2. Western blot analysis of transforming growth factor (TGF)-β2 protein in optic nerve head (ONH) cells. ONH astrocytes and lamina cribrosa (LC) cells were grown in serum-free medium for 24 h. Culture medium (20X concentrated) was subjected to western blot analysis for TGF-β2 expression. A positive band for TGF-β2 at 25 kDa was detected in western blots, indicating that ONH astrocytes and LC cells secrete TGF-β2.