VIP and head and neck squamous cell carcinoma: Emerging research highlights the contribution of cancer-derived exosomes to induce tumor axonogenesis, particularly by innervation of sensorial fibers.186,223 Head and neck squamous cell carcinomas (HNSCCs) are innervated by sensory nerves (TRPV1+, Transient Receptor Potential Vanilloid-type 1), but not by sympathetic (TH+, Tyrosine Hydroxylase) or parasympathetic nerves (VIP+, Vasoactive Intestinal Polypeptide).186 Tumor released exosomes containing EphrinB1 (EphB1, an axonal guidance molecule) induce sensory innervation of the tumor (Fig. 3).