Myeloid colony-forming assays on bone marrow cells from 8-week-old mice. (A) A bar graph depicting total colony numbers formed in 3 generations of platings by cells from Mll (n = 4), Mll/Hox (n = 6), wild-type (WT) (n = 8), and Hoxa9^–/– (n = 4) mice. Data represent means and standard errors. (B) Distribution of type I, type II, and type III colonies. Data represent means and standard errors of percentages of each colony type formed in each of the 3 generations of platings.