CD4 and leukemia: In a kinetic model studied in a cohort of 137 patients undergoing cord blood transplant, area under the curve (AUC) of ATG after infusion of the CB predicted successful CD4+ IR and event free survival (EFS), with lower levels having better outcomes and graft vs. leukemia effect (41), as has also been shown in other studies receiving PB/BM as graft source (42, 43).