Fig. 2.

Immortalized CPEB KO MEFs produce high levels of IL-6. (a) MEFs derived from WT, CPEB KO (all from different founders), or p53 KO mice were cultured according to a 3T3 protocol; the medium was harvested on the third day prior to splitting, and the IL-6 levels were determined by ELISA. The inset shows the growth curves of the 4 genotypes. (b) Acidic β-galactosidase staining of the indicated cell types at the early (presenescent), senescent, and late stages.