We show that 4-1BB antibody targeted delivery of a KLF2 siRNA to tumor bearing mice led to the downregulation of KLF2 in vaccine activated CD8+ T cells and the accumulation of phenotypically defined intratumoral CD69+CD103+ and CD69+CD49a+ CD8+ T cells which correlated with enhanced control of tumor growth. Here, KLF2 is linked to neoplasm.