These findings suggest that the ANX A1 down-regulation of PMVEC proliferation in the presence of HPS-rat-serum may be the major cause of aberrant dysregulation of cytoskeletal proteins (Destrin, a1-actin, and a1-tubulin) and may, therefore, play a fundamental role in the proliferation and phenotype differentiation of PMVECs in the PVD of HPS. This evidence concerns the gene DSTN and Hermansky-Pudlak syndrome.