STANFORD, Calif. — Macrophages—the scavenger cells of the body’s immune system—are known as troublemakers for the role they play in obesity, but Stanford University School of Medicine researchers have found that the cells can also be saviors when it comes to metabolism.The researchers highlight the beneficial role of macrophages in combating the effects of a high-fat diet in mice in a study published in the May 21 advance online edition of Nature. “Macrophages have a reputation for being the bad guys,” said the study’s senior author, assistant professor of medicine Ajay Chawla, MD, PhD. “We have found that they can also do good things.”