ATLG dosing influences graft rejection in CD3/CD19-depleted haplo-HSCT. Graft rejection occurred in 37.5% (15 mg/kg ATLG) vs 20.6% (30 mg/kg ATLG) vs 11.1% (60 mg/kg ATLG) of patients (n = 51). Associations between ATLG doses and rejection were explored using the Freeman-Halton extension of Fisher exact test (2-sided); 2-tailed probability: P = .459.