The presence of untreated periodontitis has been shown to alter the composition of the salivary microbiota (Belstrom et al., 2017) and increase salivary levels of inflammatory proteins such interleukin (IL)‐1β and matrix metalloproteinase (MMP)‐8 (Lee, Chen, Tu, Wu, & Chang, 2018; Liukkonen, Gürsoy, Pussinen, Suominen, & Könönen, 2016; Sorsa et al., 2016). The gene discussed is IL1B; the disease is periodontitis.