Reciprocal CD4+ T-cell balance of effector CD62Llow CD4+ and CD62LhighCD25+ CD4+ regulatory T cells in small cell lung cancer reflects disease stage - Koyama, K; Kagamu, H; Miura, S; Hiura, T; Miyabayashi, T; Itoh, R; Kuriyama, H; Tanaka, H; Tanaka, J; Yoshizawa, H; Nakata, K; Gejyo, F (Clin Cancer Res, 2008)