 These findings compare favorably with standard-of-care therapies for melanoma which generally lead to tumor regressions in only ~10-12% of patients.Because of the logistic difficulty of obtaining tumor-specific T cells via the ex vivo expansion of tumor-infiltrating cells, a number of studies have examined inducing these cells in vivo by vaccination.Levitsky et al., at Johns Hopkins, in a series of pre-clinical studies demonstrated that vaccine-induced T cells could be considerably more effective when re-infused into lymphodepleted recipients.