When we examined the expansion of tumor-specific CD8+ T cells using a tetramer specific for the AH1 epitope of the immunodominant 4T1 antigen gp70 in tumors that could be definitively designated ‘regressor’ or ‘non-regressor’ (day 28), we found that a significant expansion of gp70-reactive CD8+ T cells was only observed in regressing tumors (figure 1G, H). Here, CD8A is linked to neoplasm.