Figure 1. Unique kinetics of tumor onset in various tissues and organs.

The onset of superficial tumors was determined by biweekly clinical examination. Superficial tumors rarely affected mouse viability; therefore, mice bearing such tumors could be analyzed by necropsy at early and late time points for the presence of internal tumors. Kaplan-Meier curves were generated from the analysis of 180 untreated RET.AAD mice.