Previous studies have confirmed that ATG_based prophylaxis are related to superior CD8+ T, γδ T, natural killer (NK) and NKT cell reconstitution, while the reconstitution of CD4+ T, regulatory T and B cell are faster in PTCy-based GvHD prophylaxis [5, 6] Neutrophil recovers within 14–30 days after graft infusion which defends against bacterial and fungal infections, which may be delayed after PTCy treatment, resulting more infections before day 100 [6]. This evidence concerns the gene CD4 and infection.