Our new finding of TEC CD52 expression also raises the possibility that alemtuzumab leads to autoimmune complications because of a direct effect on central tolerance, as has been reported in a murine model of acute GvHD, where GvHD-induced mTEChi loss resulted in reduced tissue-restricted self-antigen expression and de novo generation of autoreactive T cells (30). Here, CD52 is linked to graft versus host disease.