Tumor antigen-reactive CTLs by programming iPS cells infiltrated into tumor tissue. Tumor antigen TCR gene-transduced iPS cells were adoptively transferred into C57BL/6 mice, which were subjected to challenge with E. G7 tumor cells. On day 35 after tumor challenge, tumor tissues were examined for tumor-reactive T-cell infiltration by immunohistological staining. Tumor antigen-specific CTLs (red) infiltrated into lymphoma tissue (green). For details, see the article by Lei and colleagues on page 4742 of this issue.