The present study utilized our recently disclosed selective MPO inactivator and clinical candidate PF-06282999, a covalent and irreversible MPO inhibitor reported in Ruggeri et al that is analogous in structure to PF-‘1355[25], to inhibit MPO activity in the low density lipoprotein receptor (Ldlr) knockout (Ldlr-/-) mouse model of atherosclerosis and assess whether MPO inhibition was able to reduce atherosclerotic plaque burden or promote atherosclerotic plaque remodeling. The gene discussed is MPO; the disease is atherosclerosis.