Growth curves of GFP and GFPdnLMP1transfected carcinoma clones. Clones of the transfected cell lines 53.217 (transgene negative; left graph), 53.234a (PyLMP1 transgene; middle graph) and 53.278a (Py LMP1 transgene; right graph) that showed the highest expression of GFP or GFPdnLMP1 were analysed for growth by neutral red assay and compared to the parental cell line in each case. Means of the four replicates (with SD) are plotted. Clone 53.234adnL-1 shows significantly different values from the parental cell line 53.234a (day 3: p < 0.0001, day 4: p < 0.0001, day 5: p < 0.0001, day 6: p = 0.0009). Similarly 53.278a clone values differ significantly from the parental 53.278a cell line (eg. for clone 53.278adnL-8: day 3: p = 0.0003, day 4: p < 0.0001, d5: p = 0.002).