IL21 and neoplasm: By the use of in vitro stimulation as a means to augment the population of antigen-specific CTL in culture and enrich for a pool of CD28hi helper-independent CD8+ T cells following exposure to IL-21, together with tetramer-guided cell sorting under clinical manufacturing conditions, it is feasible to generate tumor-reactive antigen-specific CTL of sufficient magnitude (>30 billion) for therapy in 5-6 weeks from PBMC collection to T cell product.