NRG1 and dentin dysplasia: The lightmicroscopical findings (Figure 4) were confirmed by subtle quantitative analysis of immunofluorescent signals (Figure 5): patients with DD showed a significant decrease in immunofluorescence intensity of NRG1 to 64 ± 7% (Figures 5a–c), ErbB3 to 50 ± 10% (Figures 5g,h), and nAchRb4 to 57 ± 14% (Figures 5j–l) compared to controls, while immunofluorescence intensity of ErbB2 remained unaltered (Figures 5d–f).