For this experiment, primary smooth muscle cells (SMC) were isolated from abdominal aortic aneurysm (AAA) patients. Control SMC (c-SMC) were isolated from non-dilated human aortas. SMC contraction from AAA-patients and controls was measured. SMC contraction from AAA patients shows a broad range, with higher, lower and normal contracting SMC, compared to c-smc in which a stable normal contraction is seen. We aim to understand the underlying mechanism explaining these differences in SMC contraction.