VAV1 and leukemia: Histology evaluation revealed more leukemia blasts in the peripheral blood, BM, spleen, and liver in Vav-iCre+, Baf200f/f group recipients than WT group (Fig. 7d), and flow cytometry confirmed much more GFP+ leukemia cells in the peripheral blood, BM, and spleen from Vav-iCre+, Baf200f/f group recipients (Fig. 7e).