CORRESPONDENCE

Interaction between Notch receptors and their ligands represents an evolutionarily conserved signaling pathway important not only for cell fate commitment in the developing thymus (Radtke et al., 2010) but also for regulating lineage decisions in hematopoiesis (Maillard et al., 2005). Genetic inactivation experiments showed that signaling mediated through the Notch 1 (N1) receptor plays an important role in T cell lineage commitment and maturation (Radtke et al., 1999, 2010; Wilson et al., 2001). It has been shown that Delta-like ligand 4 (Dll4