Lymphomas composed of both CD19-positive B cells and CD3-positive T-cells were observed and identified by a board-certified animal pathologist (LHR, V.M.D.)in the prostates of both controls (4/9) and Cdh1+/- mice (3/7) at 24 months of age, while neither cohort displayed lymphoma at 6 months of age (0/7 in controls, 0/3 in Cdh1+/- mice). The gene discussed is CDH1; the disease is lymphoma.