Data from two studies with 27 periodontitis patients showed no association between VEGF expression and age (≥ 50 vs. < 50 years: OR = 0.23, 95% CI = 0.02–2.72, P = 0.241) and gender (male vs. female: OR = 0.38, 95% CI = 0.05–2.87, P = 0.35) (Fig. 4a). Here, VEGFA is linked to periodontitis.