Combined mushroom polysaccharide-K (PSK, extract of Trametes versicolor (L.)Lloyd) and docetaxel treatments against human prostate cancer raise tumor-infiltrating CD4+ and CD8+ T cell numbers and increase the cytolytic activity against YAC-1 cells by splenic natural killer cells in an immunocompetent murine model, suggesting that PSK might decrease tumor growth via apoptosis and immunotherapy [27]. The gene discussed is CD4; the disease is neoplasm.