AXL and head and neck squamous cell carcinoma: Together with the effects of AXL-overexpression in SCC-25 cells, these differential results suggest that AXL can be a relevant player in HNSCC cell motility, which is in line with our observation that AXL protein expression is increased in more advanced tumor stages and lymph node metastases compared to matched primary tumors, and validates findings in other tumor entities such as neuroblastoma [28] und ovarian cancer [29].