In periodontitis, cytokines (especially TNF‐α, IL‐1β, IL‐6, and IL‐17) upregulate the expression of receptor activator of nuclear factor kappa‐B ligand (RANKL) on osteoblasts and T cells, which bind to RANK on osteoclast precursors, driving their differentiation and activation, ultimately leading to alveolar bone resorption [45]. Here, IL17A is linked to periodontitis.