The pathway enrichment for trans-eQTL egenes was largely driven by HLA genes (e.g. HLA-DRB4, HLA-C, HLA-B, HLA-DPA1, and HLA-DQA1 appear in the gene sets for graft-versus-host disease, allograft rejection, and cell adhesion molecules). Here, HLA-C is linked to graft versus host disease.