GSTM1 and acute graft versus host disease: Polymorphisms of GSTA1, GSTM1, and GSTP1 were reported as risk factors for SOS (39, 107, 116, 125) and acute GvHD (39, 107, 108, 111), while GSTA1 and GSTM1 have been associated with combined TRTs (39, 107, 108).