To further explore the relationship between Runx1 and Sgpp1 in dexamethasone‐induced apoptosis, we examined Runx1fl/fl/Mx1Cre+ B cell lymphoma lines established from a mouse model heterozygous for p53 loss and expressing c‐Myc in the B cell compartment (Eμ‐Myc). This evidence concerns the gene TP53 and B-cell non-Hodgkin lymphoma.