TRIM33 and precursor B-cell acute lymphoblastic leukemia: In murine B-ALL cells, it was demonstrated that TRIM33 is recruited by PU.1 to select lineage-specific enhancers and inhibits apoptosis in these cells by blocking activation of the pro-apoptotic gene Bim. TRIM33-deficient mice displayed selective loss of CD19 and B220 B lymphoid cells suggesting that TRIM33 is also required for normal B cell development.