Sánchez-Fernández et al. (20) investigated the effects of HA on peri-implant clinical variables and the crevicular concentrations of the pro-inflammatory biomarker's interleukin IL-1β and tumor necrosis factor α (TNF-α) in 63 patients and 104 implants in patients with peri-implantitis, finding, after 90 days, a decrease in bleeding on probing, as well as significantly lower PD values in the test group at 45 and 90 days. The gene discussed is TNF; the disease is Peri-Implantitis.