Quantitative RT-PCR analyses of the mRNA expressions of BDKRB1 (A), and BDKRB2 (B), in human gingival fibroblasts. Effects of IL-4 (50 ng·mL−1), IL-13 (50 ng·mL−1), IL-1β (100 pg·mL−1), the combination of IL-1β with either IL-4 or IL-13, TNF-α (10 ng·mL−1) and the combination of TNF-α with either IL-4 or IL-13, on the mRNA expressions of BDKRB1 (A) and BDKRB2 (B). The values represent means ± SEM for four wells per group. Samples were analysed in duplicates and normalized with RPL13A. The statistically significant effects are shown by asterisks (*, P < 0.05; **, P < 0.01; ***, P < 0.001).