CD8A and cancer: Moreover, CD8+ T cells generated by in vitro culture with WT1B peptide were cytotoxic against WT1-expressing 697 cancer cells bearing the native epitope, as demonstrated in one patient following vaccination.22 In lung cancer patients vaccinated with WT1B (six vaccinations, 12-week period), WT1A-specific CD8+ T-cell responses were detected in 5/6 HLA-A2+ patients with similar observations.23