MPO and periodontitis: Other salivary inflammatory biomarker candidate genes for periodontitis are considered, such as myeloperoxidase (MPO‐463G/A) (Erciyas, Pehlivan, Sever, & Orbak, 2010) and calcium‐binding protein A8 (S100A8) (Sun et al., 2011), Vitamin D (1,25‐Dihydroxyvitamin D3) receptor (VDR) (Chen, Li, Zhang, & Wang, 2012; Laine et al., 2012), toll‐like receptor 2, 4 (Folwaczny, Glas, Török, Limbersky, & Folwaczny, 2004; Schröder & Schumann, 2005), and lymphotoxin alpha (LTA) (Vasconcelos et al., 2012).