Fig. 5.

Proposed model for the role of LRF in B versus T lineage fate decision. In BM, where stromal cells express moderate levels of Notch ligands, LRF expression in HSCs and lymphoid progenitors functions to repress T cell-instructive signals produced by Notch (left). However, upon homing of progenitors to the thymus where Notch ligands are more abundantly expressed, this repressive role of LRF on Notch function is overruled hence allowing efficient production of T cell precursors (top right).