SRSF5 and head and neck squamous cell carcinoma: Despite the lack of information on the regulatory mechanisms of VEGF-Axxxa and VEGF-Axxxb, overexpression of splicing regulatory factors (SRSF1, SRSF5, SRSF5, and SRPK1) has been associated with the upregulation of VEGF-Axxxa isoforms in head and neck squamous cell carcinomas patients [111].