Dr. Gwendalyn Randolph is the Emil R. Unanue Distinguished Professor in the Department of Immunology and Pathology at Washington University in St. Louis. Research in her lab integrates the study of monocytes, monocyte-derived cells, and dendritic cells with vascular and lymphatic vessel biology. She discusses the work she's presenting at the American Association of Immunologists' annual meeting, IMMUNOLOGY2022, on the diversity, function, and mysteries of peritoneal macrophages.