ADRB2 and head and neck squamous cell carcinoma: Given the role of adrenergic signaling in HNSCC, it would be reasonable to postulate that directly targeting adrenergic signaling in tumor cells or indirectly targeting neuro-vascular interactions (e.g., ADRB2-NGF-VEGF signaling) within the tumor microenvironment could have significant therapeutic benefit in HNSCC.