Vaccination or treatment with a BacMam-based IL-15:IL-15Rα-expressing cell-based cancer vaccine significantly delayed the growth of B16F10 melanoma and CT26 colon cancer in mice by increasing the population of tumor antigen-specific cytotoxic T cells and stimulating memory T cell formation, as well as by facilitating infiltration of activated T cells and NK cells into tumors. Here, IL15 is linked to colonic neoplasm.