Also, GCs downregulate osteoprotegerin (OPG), an activator of the receptor activator of the nuclear factor kappa-Β ligand (RANKL) that potentially increases the activity of osteoclasts.6 Bostanci et al31 reported that RANKL and OPG were oppositely regulated in gingival crevicular fluid in periodontitis patients. The gene discussed is TNFRSF11B; the disease is periodontitis.