Cks1 knockout restores p27^kip expression but does not change tumor onset in LMP1/λ-MYC mice. (A) Representative immunohistochemical analysis of lymph node tumors from 3 to 6 mice of each genotype stained with hematoxylin and eosin, B220, and p27^kip1 using an EVOS XL microscope with 40× magnification. All tumors were isolated from the cervical area. (B) Representative immunoblots of p27^kip1 expression in tumor cells. We previously reported that the p27kip levels in LMP2A/λ-MYC/Cks1^−/− tumors were similar to WT splenic B cells.³³  (C) P27^kip1 expression was normalized to Gapdh. Dot plot graphs represent the mean ± standard deviation. P values were calculated by unpaired t test, **P < .01. (D) Kaplan-Meier curves indicate tumor-free survival percentages with or without Cks1 knockout in the background of LMP1/λ-MYC or LMP2A/λ-MYC mice.