HPS1 and polyostotic fibrous dysplasia: For example, PFD suppressed Hermansky-Pudlak syndrome (HPS)-1, alveolar macrophage cytokine and chemokine secretion in vitro in a dose-dependent manner [24] PFD was found to inhibit the responder frequency of T-cell rearrangement (TCR)-stimulated CD4 cell total proliferation in vitro and in vivo, and the proliferation index of both CD4 and CD8 was reduced.