In line with this, the group of Zhang found that EZH2 is required for both in vivo and in vitro Th1 generation and Th1-mediated graft-versus-host disease by multiple mechanisms: binding to Tbx21 promoter and inducing Tbx21 expression, and suppressing proteasome-mediated T-bet degradation14, 15. Here, TBX21 is linked to graft versus host disease.