In the same individual, peri-implantitis sites harbored more abundance of Treponema, Peptostreptococcaceae XIG-1, Porphyromonas, and Lachnospiraceae G-8, as well as cytokines of IL-6, IL-17A, G-CSF, RANTES, and IL-1β, than healthy implants sites. The gene discussed is IL17A; the disease is Peri-Implantitis.