Dubreuil et al. (2020) underscored the clinical relevance of selecting donors with a Cen-AA KIR haplotype for haplo-HSCT, proposing that these donors carry inhibitory genes associated with enhanced NK cell education and function, thereby reducing relapse risk in myeloid malignancies without increasing the incidence of GvHD [79]. This evidence concerns the gene KIR3DL1 and graft versus host disease.