Furthermore, in particular a single nucleotide polymorphism (SNP) within the HLA-DP β-chain that determines the expression levels of HLA-DP is associated with GvHD (Petersdorf et al., 2015), with high HLA-DP expression levels in the recipient being associated with a higher risk of developing GvHD (Petersdorf et al., 2015). Here, HLA-DPA1 is linked to graft versus host disease.