Figure 2. Strong infiltration of IL-21-producing CD8+CXCR5+ T cells in HCC correlates with disease stage. (A–B) Flow cytometric analysis of IL-21 production by CD8+CXCR5+ T cells (n=9). The cells were characterized using FACS with sequential gating of lymphocyte cells, CD45+ cells and then CD8+CXCR5+ cells. (A) One representative experiment is shown. (B) The data indicate the median with the interquartile range. (C–E) Immunohistochemical staining of IL-21+ cells in paraffin-embedded HCC tissue (n=96). The distribution of IL-21+ cells is shown in (C and D). Micrographs at higher magnification show the stained peritumoral liver (1), peritumoral stromal region (2), and cancer nest (3). The association of the density of tumor-infiltrating IL-21+ cells with the TNM staging of patients is shown in (E). *P<0.05, **P<0.01, ***P<0.001 and ****P<0.0001 determined using Mann-Whitney U test (B and D) or student’s t test (E).