ARG1 and periodontitis: A moderate increase in Arg1 mRNA in the anti-BAFF-periodontitis group was also observed in the ligature-induced model (Fig. 4c), and the negative correlation between alveolar bone resorption severity and the level of Arg1 mRNA was to a statistically significant extent (r =  − 0.8467, P < 0.001, n = 15; Fig. 4g).