CDC42 and Hermansky-Pudlak syndrome: As HPS‐associated PVR is mainly due to cell overproliferation and high migration ability, which has been often linked with the disruption of cell apical/basolateral polarity.11, 14 We wondered whether the rearrangement of the actin cytoskeleton and the apical/basolateral polarity loss by overactive Cdc42 were related to the changes of proliferation and migration abilities of PMVECs.