In our meta-analysis, 3 studies (32, 33, 39) evaluated three interleukins (IL-1β, IL-6, IL-8) and only two studies (33, 39) evaluated TNF-α, as indicative of mucositis; however, none of the studies included in our meta-analysis evaluated interleukins as determinants of peri-implantitis, limiting the results, exclusively to clinical parameters. The gene discussed is TNF; the disease is mucositis.