BBC3 and lymphoma: While considerably smaller than the responses observed in Eμ-Myc lymphoma cells (Figs. 2A, S3), the similarly reduced levels of induction of known TRP53-target control genes (Pmaip1, Bbc3, Cdkn1a) suggest that MEFs are overall less sensitive to TRP53-activating stimuli than Eμ-Myc lymphoma cells.