We need cholesterol. All cells require it to function. And it’s delivered to our cells via specialized particles in our blood. But sometimes these particles become trapped in the lining of our blood vessels White blood cells called macrophages clear these stuck particles by absorbing them, and processing them in compartments called lysosomes. Here the particles are broken down into their constituent parts for reclamation or disposal. Once the enzymes have done their work, the reclaimed cholesterol is returned to the blood. The problem is: Some cholesterol becomes oxidized during its travels. Oxidized cholesterol is poorly processed by the macrophages, and eventually overwhelms them, preventing them from even processing the normal cholesterol they absorb. These sick, bloated cells are called foam cells, and they attract other macrophages. But the newcomers suffer the same fate. As foam cells accumulate, they form arterial plaques which become inflamed and burst, spewing out blood clots that trigger heart attacks and strokes. But what if we gave the macrophages a new enzyme, so they can process oxidized cholesterol, too? Then, they would process stuck particles without getting poisoned and bloated, and return to healthy function. This would progressively cleanse arteries of plaque that had already formed.