Meta‐analyses comparing data from healthy patients and those with peri‐implantitis or mucositis and between patients with mucositis and those with peri‐implantitis showed a moderate predictive value of IL‐1ß, VEGF, cortisol, and sRANKL/OPG for peri‐implantitis. The gene discussed is TNFRSF11B; the disease is mucositis.