We found that effector lymphocytes mobilized with exercise, particularly effector-memory CD8+ T-cells and NK-cells, have differentially expressed genes and enriched gene sets associated with anti-tumor activity such as cytotoxicity, migration/chemotaxis, antigen binding, cytokine responsiveness and alloreactivity (e.g. graft-versus-host/leukemia). This evidence concerns the gene CD8A and leukemia.