The periodontitis modeling using B-cell-deficient CD19Cre mice showed that B-cell deficiency exacerbated periodontal bone resorption, compared with the wild-type mice, and the elevated levels of Th1 cytokines and RANKl were found in the gums of CD19Cre mice, confirming that B-cell deficiency activates Th1 and osteoclasts, which exacerbates the progression of periodontitis[85]. The gene discussed is TNFSF11; the disease is B cell deficiency.