Another important property of this model is that Trp53ER/ER mice do not develop mature T cell lymphomas [32], a feature that facilitates the analysis of the potential synergisms between Vav1 gain‐of‐function and Trp53 loss‐of‐function mutations in mature T cell lymphomagenesis without being affected by the background tumour noise usually caused when using Trp53−/− mice. The gene discussed is VAV1; the disease is T-cell non-Hodgkin lymphoma.