TNFRSF11B and Hermansky-Pudlak syndrome: Similarly, concentrations of OPG and sRANKL were both 1.5 times higher in HPS compared with NS (1383.0 vs. 894.4 pg/mL, p < 0.0001, and 438.2 vs. 290.0 pg/mL, p = 0.01, respectively) (Figure 2).