In a similar phase I clinical study based on immunotherapy by WT1 in patients with breast cancer, lung cancer, myelodisplasia and acute myelocytic leukemia, Oka et al. (Proc Natl Acad Sci USA 101 (38): 13885-90, 2004) found reduction of leukemic blast cells in leukemia, a reduction in sizes and markers of other tumors and a correlation between increase and the frequency of cytotoxic T lymphocytes specific against WT1 after vaccination against it, resulting in a regression of cancer without damage to normal tissues.