Evaluation of tumor growth, burden and age. (A) Size of largest tumor at time of analysis. There was no significant difference between the Neu deletion mutant (activated receptor) (Neu-NDL), Neu-YD and Neu-YB strains. (B) Total tumor volume at time of analysis. Transgenic mice developed multiple tumors. All tumors were measured, and the volumes were added. There was no significant difference in cumulative tumor volume, which averaged about 4 ml. (C) Average age in weeks at time of analysis. Data are means and SEM. **P < 0.005 by t-test, n = 18 to 22 mice per strain.