We previously demonstrated that neural precursor cell expressed developmentally downregulated 9 (NEDD9; human enhancer of filamentation 1, HEF-1; Crk-associated substrate in Lymphocytes, CasL) is an important regulatory protein involved in head and neck squamous cell carcinoma (HNSCC) cell signaling, leading to migration and invasion [11]. This evidence concerns the gene NEDD9 and head and neck squamous cell carcinoma.