||The basic helix-loop-helix (bHLH) family of transcription factors play roles in a variety of developmental and adult biological settings. The basic (b) domain of bHLH transcription factors allows association with DNA, while the HLH domain facilitates the mono- and heterodimeric interactions required for efficient DNA binding. TAL1, also known as SCL, is a bHLH transcription factor that plays an essential role in the generation of embryonic hematopoietic stem cells , and is required for maturation of erythroid and megakaryocytic lineages in the adult. TAL1 interacts with Lim-domain containing proteins LMO2 and Ldb1, and has been found in complexes with these proteins as well as the hematopoietic transcription factor GATA-1. Both TAL1 and LMO2 have been associated with T-cell acute lymphoblastic leukemia (T-ALL). TAL1 activity is essential for both hematopoiesis and neurogenesis.