NGF and hepatocellular carcinoma: In order to further understand the role of NGF‐NGFR communication in PD‐1 mAb anti‐tumor immunotherapy in HCC patients (Table S2), NGF‐NGFR communication was studied in 29 PD‐1‐positive patients exposed to PD‐1 mAb, 12 non‐responders, and 17 responders.