LEF-1 and the Wnt pathway are known to regulate survival in numerous cell types.[29], [30] We and others have previously shown that expression of this transcription factor by CLL cells is required for cellular survival.[5], [6] Therefore, we next wanted to evaluate whether ISC differentiated CLL cells that have decreased LEF-1 expression, also display decreased in vitro survival. Here, LEF1 is linked to B-cell chronic lymphocytic leukemia.