We identified an association of the interaction between the recipient NLRP3 SNP CC genotype and total HLA mismatches with grade 2–4 acute graft-versus-host disease (AGVHD), and an association of the interaction between the donor NLRP3 SNP T allele and HLA-C mismatch with extensive chronic GVHD (ECGVHD), in both adjusted and unadjusted regressions (P < 0.005). The gene discussed is NLRP3; the disease is acute graft versus host disease.