IL17A and periodontitis: Interestingly, while the oral commensal pathobiont‐reactive Th17 cells that arise during periodontitis exhibit a Th17 phenotype (RORγt+ T‐bet−) associated with IL‐17A but not IFN‐γ production, when these oral Th17 cells reach the gut mucosal compartment they seem to acquire a Th1‐like Th17 phenotype (RORγt+ T‐bet+) associated with IFN‐γ production (Figure 2).83