FIGURE 6 ST3GAL5 overexpression was associated with the exhaustion of CD8 + T cells in ccRCC samples of our cohort. (A) The representative IHC staining for ST3GAL5, CD8 and PD-1 in human ccRCC specimens. Case 1, low expression of ST3GAL5; Case 2, high expression of ST3GAL5. Scale bar, 250 m m; scale bar in inset, 50 m m. (B) Correlations between tumor stage and ST3GAL5 protein level (left panel), CD8 + cell density (middle panel), and PD-1 + cell density (right panel) in human ccRCC specimens (n = 45). Stage I, n = 18; Stage II-III, n = 27. (C) The correlations between ST3GAL5 level and CD8 + cell density (left panel), between ST3GAL5 level and PD-1 + cell density (middle panel), and between CD8 + and PD-1 + cell density (right panel), in human ccRCC specimens (n = 45). (D) Immuno fl uorescence co-staining of CD8 (red) and PD-1 (green) in human ccRCC specimens with low (upper panel) and high (lower panel) expression of ST3GAL5. DAPI (blue) was used for nuclei staining. Scale bar, 50 m