Furthermore, the density of CD4+CD25+ cells showed a high positive correlation with the density of Foxp3-expressing cells but a high negative correlation with the density of granzyme B-expressing cells in HCC tissues (r = 0.6508, P < 0.0001; r = − 0.5548, P = 0.0002, respectively) (Fig. 5D,E). Here, GZMB is linked to hepatocellular carcinoma.