The cumulative incidence of total chronic GVHD (cGVHD) at 2 years after preemptive immunotherapy was 45.1% (95% CI, 32.4%−57.8%) in patients receiving IFN-α therapy alone, 57.1% (95% CI, 4.4%−100.0%) in patients receiving DLI alone, and 75.3% (95% CI, 58.6%−92.0%) in patients receiving both DLI and IFN-α therapy (p = 0.154). Here, IFNA2 is linked to chronic graft versus host disease.