CXCL12 gene polymorphism (rs1801157) affects the outcome of unrelated HSCT.
CXCL12-3′-A allele in donors associates with lower risk of toxic complications.
Acute GvHD incidence is lower in patients having CXCL12-3′-A allele and AA homozygous genotype.
CXCL12-3′-A-positive patients are less prone to early HHV-6 reactivation.
CXCL12-3′-A variant plays a beneficial role in unrelated HSCT.