Patients who received emapalumab before HSCT required less interventions for mixed chimerism after HSCT. Cumulative incidence of interventions performed for mixed chimerism included rapid taper of immunosuppression (cyclosporine or tacrolimus) (A), DLI (B), CD34-selected boost (C), and second HSCT (D). Death was included as a completing risk; incidence was analyzed using the Mantel-Cox or log-rank test. ∗P < .05. ns, not statistically significant.