Interestingly, they also observed increased levels of Notch Dll1 ligand on CD4+ FoxP3+ T cells, but not on other cell types, and suggest that constitutive Akt activation may induce expansion of T cells overexpressing Dll1, in turn sustaining Notch1 activation and facilitating CLL to RT transformation. Here, DLL1 is linked to B-cell chronic lymphocytic leukemia.