As a consequence of its oncogenic potential and presumptive immunogenicity, WT1 was ranked top in a list of tumour‐associated antigens prioritized for cancer immunotherapy.1 Indeed, spontaneous T‐cell responses against WT1 are induced in patients with leukaemia after allogeneic stem cell transplantation or donor lymphocyte infusions2, 3, 4 and are associated with disease regression.4 WT1‐specific T cells may also be involved in cancer immune surveillance. The gene discussed is WT1; the disease is leukemia.