While our data are in agreement with most previous studies which suggest a relationship between the IL6-174 GG genotype of the recipients and an increased risk for development of acute GVHD (Ambruzova et al. 2009; Cavet et al. 2001; Dickinson and Charron 2005; Dukat-Mazurek et al. 2017), other authors did not observe an association between IL6-174 SNP and acute GVHD (Lin et al. 2003; Mullighan et al. 2004; Tvedt et al. 2018). This evidence concerns the gene IL6 and acute graft versus host disease.