<p>The invention relates to the novel use of gene markers in a method of predicting the risk of or diagnosing a subject to develop graft versus host reaction (GvHR) or graft versus host disease (GvHD). In other aspects the invention also relates to methods of monitoring the efficacy of treatment of GvHR or GvHD, and methods of screening a candidate substance for the treatment of GvHR or GvHD.</p>
