LY3000328 is a potent cathepsin S inhibitor (IC50 = 7.7 nM for the human enzyme). It is selective for cathepsin S over cathepsin L, K, B, and V (IC50s = >10,000, >10,000, 4,390, and 21,500 nM, respectively). LY3000328 (1-30 mg/kg) reduces aortic diameter in a mouse model of calcium chloride-induced abdominal aortic aneurysm.