FIGURE 4.

A significant radial velocity bias is required to fit the U87WT with a reasonable set of parameters, as shown in column 3. The mathematical model (line) was optimized to fit the experimental data (dots) for the two cell lines. Each column uses a different set of parameters, given at the top of the column. Column 1 shows the best fit to the U87ΔEGFR data. Notice that in column 1, v_i = 0.001 cm/day, which is quite small. Column 2 shows the result when we fix v_i = 0.02 cm/day to be as large as it is for U87WT, and then optimize the other parameters to achieve the best fit. We see that the model cannot fit the data and that U87ΔEGFR cannot have an equally large velocity bias.