{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"LEF-1 (Lymphoid Enhancer-Binding Factor 1), normally expressed in pre-B and T cells, is a member of the lymphoid enhancer binding factor/T cell specific transcription factor (LEF/TCF) family of DNA-binding transcription factors. LEF-1 is a key component of the Wnt signaling pathway, which regulates cell proliferation, differentiation, and survival during embryonic development and tissue homeostasis. LEF-1 complexes with Groucho/TLE and act as transcriptional repressors, then upon activation of the Wnt pathway, β-catenin displaces Groucho/TLE and binds to LEF-1 to promote the expression of Wnt target genes involved in cell fate determination and tissue morphogenesis. LEF-1 overexpression has been observed in several cancer types, including colorectal cancer, breast cancer, melanoma, and leukemia. Strong nuclear expression of LEF1 is observed in the majority of chronic lymphocytic leukemia/small lymphocytic lymphoma cases, and high levels of LEF-1 is also associated with more aggressive tumor behavior, higher tumor grade, and poorer prognosis in certain cancer types."}]}]}