Transcription factor dose links development to disease

Abstract

In this issue of Blood, Simmons et al report that low expression levels of the transcription factor Pax-5 in B-lineage progenitors results in the formation of highly proliferative B220+CD11b+ cells expressing both lymphoid and myeloid genes much in resemblance to cells generated in acute lymphoblastic leukemia (ALL)-like bi-phenotypic acute leukemia (BAL). 1 In contrast, high expression levels of Pax-5 in the progenitors result in expression of CD19 and apparently stable B-lineage commitment, suggesting a critical role for Pax-5 dose in both normal B-cell development and in the generation of leukemia. (Figure Presented).