Peripheral blood chimerism. Shown over time after competitive bone marrow transplantation with cells from 45.2 Tet2-null mice (A) and 45.2 Tet2-WT mice (B). Gray bars indicate periods of treatment with AZA or vehicle. Tet2-null cells show increased chimerism compared with Tet2-WT cells. Treatment with AZA significantly decreases chimerism in the Tet2-null recipient mice only. *P < .05, **P < .01.