In the same time, BDNF genotype GG was correlated with higher levels of BDNF, TNF-α, and the chemokine CXCL10 in patients with chronic periodontitis (Corrêa et al., 2014), while 5-HTTLPR polymorphism was associated with aggressive periodontitis (Costa et al., 2008; Mendes et al., 2013). Here, BDNF is linked to chronic periodontitis.