A scheme of 3 different types of NIMA-complementary HLA-haploidentical stem cell transplantation. (A) Stem cell transplantation (SCT) from mother to offspring: GVH reaction is directed against the inherited paternal HLA antigens (IPA), while HVG reaction is directed against the NIMAs of offspring 1 (Mb). (B) SCT from offspring to mother: GVH reaction is directed against the NIMAs of offspring 2 (Ma), and HVG reaction is directed against IPAs. (C) SCT between NIMA-mismatched siblings who shared the inherited paternal HLA haplotype: These siblings are bidirectionally mismatched for NIMAs in both the GVH and HVG directions.