CD4 and neoplasm: As expected, tumor-derived TGF-β1 established a systemic immunosuppressive environment that was represented by an increase of the CD4+Gr11b+ T-cell population and a decrease of the activated subpopulation of CD4+CD44+CD62L– T cells in lungs and spleens and CD8+IFNγ+ T cells in spleens (Fig. 4a–c).