ACE and cervical squamous intraepithelial neoplasia: (D) Concomitant use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers: the role of renin-angiotensin-aldosterone system blocking agents such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in the pathophysiology of CIN remains controversial.