By contrast, the immune and inflammatory pathways (i.e., graft-versus-host disease, allograft rejection, antigen processing and presentation, the chemokine signaling pathway, the C-type lectin receptor signaling pathway, Th1 and Th2 cell differentiation, Th17 cell differentiation, and the T cell receptor signaling pathway) were significantly downregulated (p < 0.05), accounting for nearly one-third of all downregulated pathways (Supplementary Table S4). This evidence concerns the gene CLEC4D and graft versus host disease.