CD4 and malignant colon neoplasm: Although some studies have shown that several tumor cells can generate CD4+CD25+ regulatory T cells from peripheral CD4+ naïve T cells through the secretion of TGF-β [23], [24], [25], other has demonstrated that the levels of the cytokines of TNF-α, interleukin (IL)-1β, IFN-γ were increased during the interaction between colon cancer cells and lymphocytes [26].