In view of the ever-increasing recognition of the essential role of prostacyclin and its receptor for vascular integrity and in counter-balancing/off-setting various types of vascular diseases including thrombosis, systemic hypertension, stroke and myocardial infarction [5–8], these studies provide important mechanistic insights into how hIP, and/or indeed Rab5, dysfunction may contribute to such disease processes. Here, RAB5A is linked to Hypertension.