Figure 2. Cytotoxic effects of chaetocin on cell viability of ccRCC cell lines A-498 (A) and CAKI-2 (B). Both cell lines were incubated in medium containing 0–400 nM chaetocin and the cell viability was determined after 1 day (red) and after 4 days (blue) by the use of the MTT assay. Triplicates were used for each sample to determine the mean ±SD. The significance was determined by the use of t-test (*=0.05–0.04, **=0.02–0.03, ***=<0.002). Cells without chaetocin treatment were used as negative control while cells treated with a deadly dose of DMSO were used as positive control.