For instance, in human, IL-4-producing CD161+CD4+ iNKT cells suppressed T cell expansion, CD4-CD94+ iNKT cells with high cytotoxicity could destroy antigen-presenting cells in the recipients, HLA-II+CD161- iNKT cells (mixture of CD4+ and CD4- cells) that were more Th1 polarized but less cytotoxic correlated with exhaustion and GvHD (61). This evidence concerns the gene KLRB1 and graft versus host disease.