STAT3 and head and neck squamous cell carcinoma: NK cells and macrophage in nude mice32 might infiltrate into the xenograft tumors, causing up‐regulation of IL‐6 and PD‐L1 in tumor microenvironment.33, 34 The expression of IL‐6/STAT3 and PD‐L1 of the HNSCC xenografts and its immunological mechanism after LfcinB injection is worthwhile for investigation in the further studies.