Figure 2

Characterization of the immune cell infiltrate in GEP-NETs. (a–d) Serial sections of a pancreatic neuroendocrine tumor. (a) Intense staining for CD3 in TILs of NET tissue. (b) Staining for FOXP3 in some TILs. (c) Staining for PD-1 in some TILs, (d) hematoxylin-eosin staining. Original magnification with 20x and 40x (insets). Scale bar for 100 µm is represented with a line for each panel. (e) CD3, (f) FOXP3 and (g) PD-1 were measured by IHC in a set of TMAs (n = 164) of GEP-NETs, including primary and metastatic tissue. Values represent boxplot of CD3 IHC score and bar graphs of the percentage of samples with positivity for FOXP3 and PD-1 expression in the tumor tissue and in the peritumoral normal tissue. Asterisks indicate significant differences between tumor and peritumoral tissues (p-values for Fisher’s Exact Test: *p < 0.05). (h–k) Immunofluorescence showing different markers in TILs: h) Double immunofluorescence with CD3 (green) and PD-1 (blue). (i) Double immunofluorescence with CD3 (green) and FOXP3 (red). (j) Double immunofluorescence with PD-1 (blue) and FOXP3 (red). (k) Triple immunofluorescence with CD3 (green), PD-1 (blue) and FOXP3 (red). Scale bar for 100 µm is represented with a line for each panel.