This is part 3 of our series on David Sinclair's new book, "Lifespan: Why We Age and Why We Don't Have To." We'll talk about 3 concepts—rapamycin, mTOR, autophagy. Rapamycin (an antibiotic) inhibits mTOR (a protein). mTOR inhibits autophagy. Autophagy is a natural process by which the body eliminates unnecessary components (like dead mitochondria). So, does rapamycin have an effect on aging and longevity? That's what we'll discuss in the podcast.