VEGFA and head and neck squamous cell carcinoma: Thus, molecules of several growth factors activate intracellular inositol 1,4,5‐triphosphate (IP3), which in turn binds to its receptor and initiates releasing of Ca2+ stored in the endoplasmic reticulum into the cytoplasm.[27, 28, 29] VEGF‐A, one of such growth factors, is abundant in HNSCC tumor environment.