Introduced at the contraction phase after immunization with an artificial adjuvant vector cell (aAVC), an IL-2/anti-IL-2 monoclonal antibody complex (IL-2Cx) combination activated stem-like subsets that correlated with therapeutic responses, and induced long-term memory CD8+ T cells that conferred protection against tumor rechallenge in a leukemic model (148). Here, IL2 is linked to neoplasm.