MYC and neoplasm: Strikingly, tumor onset in the LMP2A/λ-MYC/p27Super mice was 172 days later than that in the λ-MYC mice, and there was no significant difference in tumor onset between the LMP2A/λ-MYC/p27Super and the λ-MYC/p27Super mice, which had a median tumor-free survival time of 400 days.