Given the implication of Vav1 in positive and negative TCR selection events in thymocytes, it could be speculated that the perturbation of thymic development or, alternatively, the lack of elimination of immature T–cells carrying tumorigenic rearrangements of antigen receptors in Vav1–/– mice could create a pool of tumorigenic events that may eventually increase lymphoma development rates in those animals. This evidence concerns the gene VAV1 and lymphoma.