The immune system plays a central role in organismal health. While immune cells are present in large numbers in most healthy tissues, supporting their normal function, changes in immune cell numbers or activity are relevant to virtually every disease. For those reasons, I devote my work to understanding how immune cells influence physiology and pathology. One of my most relevant contributions was the identification of macrophages as key players in cardiac function through the removal of mitochondria and other damaged components from cardiomyocytes. The phenomenon, that we refer to as heterophagy, established a new paradigm where specialized post-mitotic cells rely on immune cells to eliminate their waste products and maintain metabolic stability.