Table 1.

Three non-exclusive genetic concepts or models in genetic susceptibility to graft-versus-host disease after allogeneic stem cell transplantation.

Model	Mechanism	Examples	Study tools
High/low responder	Genetic variants leading to differences in strength of alloimmune response	Genetic polymorphisms in TNF or IL10 genes	Case (GvHD pos) – control (GvHD neg) associations; GWAS; functional genomics; eQTL
Matching	Amino acid or expression differences in proteins between donor and recipients leading to immune activation	HLA; deletions; minor histocompatibility antigen; genome level matching scores	Genomic level or candidate gene differences in each transplantation case; proteogenomics
Pharmacogenetic	Genetic variation in genes related to the effects of the drug	SNP in IMPDH1 gene	Association of drug levels or metabolism with genetic variation in patient and with GvHD; detailed in vivo measurements of drug levels