Some of the studies carried out on peri-implant soft tissues in humans with peri-implantitis have analyzed transforming growth factor beta (TGF-β), interleukin-17 (IL-17), cluster of differentiation 31 (CD31), collagen fibers, and metalloproteinases, among others [19,20,21]. The gene discussed is PECAM1; the disease is Peri-Implantitis.