CD8A and neoplasm: However, although IFNγ secreting tumor-specific CD8+ T cells were not detected post therapy, depletion of CD8+ T cells during the course of therapy appeared critical for generation of immunological memory as over half of these mice were not protected from rechallenge, in agreement with a previous report.19 Given that CD4+ T cell depletion also reduced protection from rechallenge it is likely that both T-cell subsets are acting in concert to prime long-term immunological memory.39