Flow cytometry analyses of CD8 T cells from mice challenged by parental MC38 and its IL-15Rα–transfected clone. Lymphocytes were separated (day 1, day 4, day 7, and day 14 after injection) from spleens of wild-type mice challenged by MC38 cells or their IL-15Ra transfected clone (mIL-15Rα⁺ MC38) and were analyzed for their expression of surface markers (CD8 versus CD69 or CD8 versus Asialo GM1) by flow cytometry.