CD4 and neoplasm: Immunohistochemical analyses revealed that total CD4<sup>+</sup> T cell infiltration was unchanged, whereas CD8<sup>+</sup> cytotoxic T cell infiltration was markedly increased and FoxP3<sup>+</sup> regulatory T cells were significantly reduced in tumours from p110γ-deficient mice, resulting in a substantially elevated CD8<sup>+</sup>/FoxP3<sup>+</sup> ratio.