TNF and graft versus host disease: These data may suggest that IL-15 SA may aggravate GVHD in allogeneic, though we have not seen this in our low dose T cell models Interestingly, IL-15SA increases IFN-g and TNF-a secretion from slow proliferative CD8 (+) T cells that may resemble the more homeostatic expansion of T cell in the lymphopenic environment [10, 25, 28]