CD4 and neoplasm: In this study, we demonstrated that whole β-glucan particles (WGPs) could activate and maturate DCs, and up-regulate the GITRL expression on DCs both in vitro and in vivo, thus promoting the proliferation of CD4+CD25− effector T cells, leading to augmented cytotoxic T lymphocyte (CTL) responses via GITR/GITRL interaction in tumor models.