A total of 49 in the group of recipients’ IL6-597 SNP developed chronic GVHD: 22 of 91 patients (24.2%) with the GG genotype, 8 of 59 patients (13.6%) with the AA genotype and 19 of 149 patients (12.8%) with the GA genotype. This evidence concerns the gene IL6 and chronic graft versus host disease.