The aim of our analysis was twofold: to assess the effect on transplant outcomes of combining PTCy with calcineurin inhibitor + mycophenolate mofetil (MMF) instead of mTOR inhibitor + MMF for GvHD prophylaxis, and to assess the effect of stratification by conditioning intensity in the setting of haplo-HCT. This evidence concerns the gene MTOR and graft versus host disease.