Adenoviral-mediated antitumor capacity in renal cancer cells. Ketr-3, OSRC-2,786-O, ACHN and HK-2 cells were exposed to Ad5-ZD55, F5/35-ZD55, Ad5-ZD55-Hep27 and F5/35-ZD55-Hep27 at a various MOIs (0.1, 1, 10, 50 and 100) for 48 h, respectively. Cell viability was measured using the MTT assay. Relative cell viability was calculated compared to the control group, which was set at 1. The data were expressed as mean values + SD (n = 6). Statistical significance was determined using Student's t test. The data were representative of three separate experiments. * means P < 0.05, ** means P < 0.01.