1991;9:389-93. Marzo AL, Kinnear BF, Lake RA, et al. Tumor-specific CD4+ T cells have a major “post- licensing” role in CTL mediated anti-tumor immunity. J Immunol. 2000;165:6047-55. Maslak PG, et al. Blood; 2007;110:903, Abstr. # 90.