The immunogen for the anti-LEF-1 antibody was a full length protein. Lymphoid Enhancer Factor -1 is a transcription factor of the High Mobility Group of DNA binding proteins. It is one member of a family of four proteins referred to as LEF/TCF transcription factors (LEF-1, TCF-1, TCF-3 and TCF-4). These factors play a crucial role in WNT/WIngless signaling, a signal transduction cascade that directs cell differentiation. Aberrant activation of the WNT/Wingless pathway is also a root cause in the genesis of certain cancers such as colon cancer, melanoma and breast cancer.LEF-1 is expressed during development in many different differentiating tissues, and in a few tissues after birth. LEF-1 expression is required for proper development of breast, teeth, hair, whiskers and the trigeminal nerve. It is redundant with TCF-1 (for T Cell Factor-1) for correct development of T lymphocytes in the thymus. LEF-1 is a 399 amino acid protein that appears as a cluster of [polypeptides ranging in size between 55-57 kD on SDS-PAGE analysis. Alternative splice forms of LEF-1 and other LEF/TCF family members have been identified, but the expression pattern and relative abundance of these alternative forms have not been well studied. They can appear on westerns as smaller immunoreactive forms.