CD28 and acute lymphoblastic leukemia: In order to evaluate the capacity of UCX® cells to modulate T-cell activation, peripheral blood mononuclear cells (PBMCs) from 2 different donors were stimulated with anti-CD3, anti-CD28 and IL-2 while co-cultured with irradiated UCX® cells, bone marrow-derived mesenchymal stem cells (BM-MSCs) and tumor cells belonging to an acute lymphoblastic leukemia adult cell line (Molt4) as non-MSC control.