FN1 and neoplasm: The TME in HNSCC comprises many different cell populations, such as tumor cells, tumor stromal cells, namely, stromal fibroblasts, endothelial, and various infiltrating immune cells (neutrophils, macrophages, regulatory T cells, myeloid-derived suppressor cells, natural killer cells, platelets, and mast cells), and heightened non-cell components of the extracellular matrix (ECM) such as collagen, fibronectin, hyaluronan, laminin, among others (57, 59–61).