In vivo: No significant impact on total numbers of CD45+ or CD45+CD3+ T leukocytes; deeper tumor infiltration of CD8+ T cells, which also were positive for activation markers (granzyme B, CD107a, IFN-γ, CD25, CD69, and CD44); downregulation in Treg populations in tumors. Ex vivo: Antigen-directed cytotoxicity against malignant cells and stimulation in the uptake of glutamine by CD8+ T cells; increase in the effector memory T cell population (CD44+CD62L+). The gene discussed is CD8A; the disease is neoplasm.