FOSL1 and head and neck squamous cell carcinoma: FOSL1 is an AP‐1 transcriptional factor which has been confirmed to promote invasion, stemness and metastasis in HNSCC.[8, 9, 14] Importantly, we showed that FOSL1 enhanced the tumorigenicity and metastasis of HNSCC predominantly via selective association with Mediators to establish SEs in our previous studies.[9, 15]