At 18mo of age, there was significant splenomegaly (spleen weight 611mg vs 89mg, P<0.001), increased total spleen cell counts (267 vs 153 x 106 cells per spleen, P=0.031), and decreased total marrow cell counts (23 vs 58 x 106 cells per femur, P<0.001) in the Tie2FF1 mice compared to age-matched Tie2-cre control mice (Figures 1C–E). The gene discussed is TEK; the disease is Splenomegaly.