EPHB4 and head and neck squamous cell carcinoma: Given their high specificity for their targets (EphB receptors and EphA4 for ephrinB2-Fc-His or EphB4 for Fc-TNYL-RAW-GS), the two Fc fusion plasmids are promising agents to combat HNSCC metastasis and circumvent off-target effects of traditional receptor tyrosine kinase inhibitors [74–76, 116].