Cantrell’s group has also shown that the elimination in thymocytes of RhoA function, a GTPase activated by Vav family proteins, leads to a lymphoblastic lymphoma very similar to the disseminated tumors found in Vav1–/– and Vav1–/–;Rasgrf2–/– mice [29]. The gene discussed is RASGRF2; the disease is lymphoblastic lymphoma.