JAG1 and leukemia: Contact with MSCs enhances Notch1, Jagged1, and CD28 expression on T-ALL cells (Yuan et al., 2013) and promotes leukemia cell homing into BM niche in xenotransplantation models; on the other hand, IL-6, SCF, HIF-1α, VEGFα, and Notch ligand Jagged1 is overexpressed in stromal cells (Wang et al., 2016).