NOS2 and periodontitis: The possible influence of a genetic component on the secretion of nitrates (III) and (V) in periodontitis is indicated by studies on the Brazilian population, which have shown that heterozygotes for two polymorphisms of the NOS2 -1026 (A > C) rs2779249 and +2087 (A > G) rs2297518 gene with CP secrete significantly less salivary nitrates (III) and (V) [37].