BCL6 and graft versus host disease: In addition, Deng discovered the pathogenesis of GVHD is related to the expansion of extrafollicular PSGL-1lowCD4+ T cells, and blockade of donor CD4+ T cells by ICOS, BCL6, or STAT3 prevents the expansion of PSGL-1lowCD4+ T cells, which would improve the induction of GVHD [78].