The changes of CD4+CD25+/CD4+ proportion in spleen of tumor-bearing BALB/c mice

CD4+CD25+ regulatory T lymphocytes (TR) constitute 5–10% of peripheral CD4+ T cells in naive mice and humans, and play an important role in controlling immune responses. Accumulating evidences show that TR cells are involved in some physiological processes and pathologic conditions such as autoimmune diseases, transplantation tolerance and cancer, and might be a promising therapeutic target for these diseases.