Stem cells and cancer cells share some properties, which has led to the hypothesis that irradiated stem cells might be used as a vaccine for cancer treatment. Kooreman, Kim et al. tested this hypothesis using induced pluripotent stem cells (iPSCs). They first observed that both human and mouse iPSCs express tumour-associated antigens and then developed autologous vaccines from irradiated iPSCs created from mouse fibroblasts. These irradiated iPSCs plus the adjuvant CpG prevented tumour growth in mice that were later injected with melanoma, mesothelioma or breast cancer cells. In addition, although the iPSC vaccine could not eradicate established melanomas, administration following partial surgical removal of tumours prevented recurrence. Furthermore, the immune response was shown to be cancer-specific, as adoptive transfer of T cells from vaccine-treated mice inhibited tumour growth in unvaccinated mice. No adverse effects were observed, supporting the potential for clinical translation.