CSF3 and head and neck squamous cell carcinoma: Although other proteins might modulate EV migration, in our transwell experiments, untreated HNSCC-derived sEV promoted migration of the responder endothelial cells, and neutralizing Abs to April, GCSF or IL-22, but not IgG control Abs, blocked the sEV-driven cell migration (SFigure 2B).