CD4 and neoplasm: Further investigation of the TILs in the 50 patients with G1/G2/G3 NETs showed that the levels of CD3+/CD4, and CD3+/CD8 TILs were not different, but those of CD3+/PD-1high and CD204+/PD-L1high populations were significantly higher in higher grade NET tumours (Fig. 4).