VEGFA and viral infectious disease: It is notable that VEGF appears to be able to act as growth factor for not only vascular endothelial cells but also epithelial cells in mouse models.21 Moreover, the absence of EGFR-expressing CD163+ macrophages in the tongue mucosa of bluetongue virus-infected or healthy sheep clearly indicates that the expression of this receptor is not the result of generic viral infection but may be unique to ORFV infection.