Why Does COVID-19 Boost Stroke Risk? A UCLA-led study using 3D-printed “blood vessels” aims to identify a possible link between coronavirus and stroke. The study was published in In the study, UCLA researchers used a 3D-printed silicone model of blood vessels in the brain to mimic the forces generated by blood pushing through an artery that is abnormally narrowed, a condition called intracranial atherosclerosis. They showed that as those forces act on the cells lining the artery, and increase the production of a molecule called angiotensin-converting enzyme 2, or ACE2, which the coronavirus uses to enter cells on the surface of blood vessels.