About the Cover
Macrophages are a heterogeneous population of tissue resident hematopoietic cells. This figure illustrates key cell surface markers of mouse macrophage and monocyte populations. Macrophages can be identified by a combination of cell surface markers, including the hematopoietic lineage marker CD45, the integrin CD11b, and the GPCR F4/80, among other markers. However, macrophages in different organs have different compositions and expression levels of these cell surface proteins, reflecting their inherent diversity. CD169, sialoadhesin, is an important marker in certain macrophage populations such as the bone marrow, spleen, and lung. CX3CR1 helps to identify macrophages in the intestine and to differentiate the blood monocyte subsets. For details, see the Masters of Immunology article by Lavin and Merad on page 201 of this issue.

About the Master
Miriam Merad, MD, PhD, is Professor of Oncological Science in the Department of Medicine and Immunology and a member of the Immunology Institute and The Tisch Cancer Institute at the Mount Sinai School of Medicine in New York. Dr. Merad received her MD from the University of Algiers, Algeria. She did her residency in hematology and oncology in Paris, France, and obtained her PhD in immunology in collaboration between Stanford University and University of Paris VII. She was recruited to Mount Sinai School of Medicine in 2004 and was promoted to the rank of associate professor with tenure in 2007 and to full professor in 2010.
In 2010, Dr. Merad became the program leader of the Cancer Immunology Immunotherapy Group at The Tisch Cancer Institute and the director of the Human Immunomonitoring Center. Dr. Merad also serves as the associate director for the MD/PhD Program at Mount Sinai Medical School.
Dr. Merad's laboratory studies the mechanisms that regulate the development and function of innate myeloid cells, including dendritic cells, Langerhans cells, and macrophages. The Merad laboratory has made seminal discoveries in Langerhans cells and macrophage biology revealing their embryonic origin and their local maintenance in situ. Dr. Merad's laboratory has also extensively studied the mechanisms that control dendritic cells and macrophage homeostasis and function in barrier tissues such as the skin, lung, and gut. More recently she joined the ImmGen Consortium to help decipher the transcriptional regulation of the tissue dendritic cell and macrophage lineage. Currently, one of the major goals of the Merad laboratory is to identify the contribution of innate myeloid cells to disease outcome, including cancer and microbial immunity.
Dr. Merad has authored more than 100 primary papers and reviews in high-profile journals and obtained extensive NIH funding for her studies on dendritic cells and macrophage biology in mice and humans.