MAS1 and periodontitis: The ligature-induced periodontitis significantly increased the Mas relative RNA expression in wide type mice (WT-L) and AT2 knockout mice (AT2-L), when compared to their control groups, WT-NL and AT2-NL (p < 0.001 and p < 0.001, respectively) (Figure 3), and in the AT1-L knockout mice, p < 0.001 (Figure 3).