However, some studies have shown that various proteins involved in tumorigenesis are differentially expressed in papillomas and associated with malignancy, such as chemokine (C-X-C motif) ligand (CXCL) 1, CXCL6, CXCL8, and vascular endothelial growth factor (VEGF)-A. This evidence concerns the gene VEGFA and papilloma.