The study of Aspriello et al. [66] described VEGF cytoplasmic expression by immunohistochemical staining (IHC) in endothelial cells of gingival tissue samples of 66 patients with periodontitis, including 22 patients with type II diabetes mellitus (T2DM), 22 patients with type I diabetes mellitus (T1DM), and 22 systemically healthy subjects. This evidence concerns the gene VEGFA and periodontitis.