Figure 3.

Enhanced tumor development in TGB6F1 mice with the Arg¹² mutant ras peptide. Five mice per group were immunized with the Arg¹² mutant ras peptide in CFA, the Leu⁶¹ mutant ras peptide in CFA, or with saline in CFA. Pictures were taken 1.5 wk after the end of promotion (mice anesthetized for photography). Although the difference between the specifically immunized and the control groups is apparent, the bottom panel shows that papillomas developed more slowly in one of the five Arg¹² mutant ras peptide–immunized mice, and some of the papillomas in the Arg¹² mutant ras of the other four similarly immunized group remained small. The results shown here and in Fig. 2A and Fig. B are derived from the same experiment; pictures shown here were taken 1 wk earlier than results shown for the same mice in Fig. 2 B.