CXCL-8 production by gingival epithelial cells is dependent on the composition of the microbial community (Belibasakis et al., 2013), and data on CXCL-8 levels in the gingival crevicular fluid of periodontitis patients are still contradictory (Finoti et al., 2017). This evidence concerns the gene CXCL8 and periodontitis.