Figure 6. TGZ at 10 μM has no effect on ARPE-19 cell proliferation either in the presence or absence of TGFβ2.ARPE-19 cells were either left untreated or treated with 10 μM TGZ, 0.05% DMSO, or 4 ng/ml TGFβ2, or were treated with TGFβ2 combining with TGZ or DMSO for 48 h as indicated. Cell viability was estimated by MTT assay (A) or trypan blue exclusion assay (B). TGZ at 50 μM is cytotoxic and used as positive control of trypan blue exclusion assay. Bars represent the mean ± SD *p<0.05 versus untreated cells.