CXCL8 and head and neck squamous cell carcinoma: It was also found that treatment with vitamin D3 may promote reductions in the pro-angiogenic and pro-tumourigenic factors VEGF and IL-8, as well as IL-1α and IL-1β, in the HNSCC tissue; however, significant elevations in both proangiogenic cytokines VEGF and IL-8 were noted.