Validation of selected targets in pretumor and tumor B cells. RNA was isolated from purified B cells from 3-week-old λ-MYC and LMP2A/λ-MYC mice (A) or cervical lymph node tumor cells from tumor-burdened λ-MYC and LMP2A/λ-MYC mice (B) and converted to cDNA. Real-time RT-PCR analysis was performed using primers specific for the indicated target gene as well as the housekeeping gene Hprt. Each bar represents the average ΔΔC_t for at least 3 different mice, and the ΔΔC_t was calculated using one of the 3 individual λ-MYC mice as the reference sample to set the baseline for each gene. Error bars represent SEM. *P ≤ .05. ***P ≤ .01. (C) Immunoblot analysis shows Egr1 expression in tumor cells from LMP2A/λ-MYC mice and λ-MYC mice. Each lane represents a single tumor of the indicated genotype, and the data are representative of several immunoblot analyses.