Heart transplant recipients were randomly assigned to six groups (n = 10): Group 1, rGST alone; Group 2, untreated control; Group 3, PBS alone; Group 4, Flt3L alone (10 mg/day, i.v) for 10 consecutive days before heart transplantation; Group 5, Rapa alone (2 mg/kg/day; p.o, POD0-15); Group 6, combination treatment of Flt3L and Rapa.