Figure 1. Context dependent integration of p53 tumor suppressor activities. The study by DeMicco and colleagues shows that the role that p53 plays in suppressing neoplastic transformation can vary by developmental stage within a single cell lineage.⁴ Their data show that inactivation of TP53 in HSC results in tumors with translocations that do not involve antigen receptors, while inactivation in DN thymocytes predisposes to lymphoma with antigen receptor translocations. These lymphomas contrast with the aneuploid tumors that arise after germline inactivation of TP53. This highlights the developmental context dependency of p53 functions.