The feasibility to expand leukemia-specific CTLs from healthy donors by leukemia antigen-derived peptide stimulation had been first shown in the setting of chronic myeloid leukemia (CML) by using the B-cell receptor-ABL (BCR-ABL) p210 fusion protein, proteinase 3 (Pr3) and Wilms’ tumor antigen 1 (WT1) antigens [36], and subsequently replicated for BCR-ABL p190 [35], WT1 alone [37,38] or combined with multiple antigens including Pr3, human neutrophil elastase (NE), melanoma-associated antigen A3 (MAGE-A3), preferentially expressed antigen in melanoma (PRAME) and survivin [11,18,39]. The gene discussed is PRTN3; the disease is leukemia.