Disease Outcomes Are Influenced by the Yang (M1) or Yin (M2) of Macrophage FunctionRosenthal, Kenneth S. PhD; Drakovac, Sanjin BS; Stone, Sarah BSInfectious Diseases in Clinical Practice: July 2012 - Volume 20 - Issue 4 - p 272–276 doi: 10.1097/IPC.0b013e318255d58a Immunology/Microbiology in ID Abstract Author Information Although possibly an oversimplification, macrophages can be divided into 2 major categories based on whether they promote antimicrobial inflammation (M1) or facilitate cleanup and wound healing (M2). These are the fight or fix functions of macrophages. These types are influenced by microbial, cytological, innate, and immune stimuli and reinforced by TH1 and TH2 CD4 helper T-cell responses. The M1/M2 designation provides a useful paradigm for dissecting the influences and outcomes of innate and immune responses to infections, vaccines, wounds, tumors, and obesity as well as designing appropriate immunotherapy. From the Northeast Ohio Medical University, Rootstown, OH. Correspondence to: Kenneth S. Rosenthal, PhD, Northeast Ohio Medical University, 4209 SR 44, Rootstown, OH 44272. E-mail: email@example.com. The authors have no funding or conflicts of interest to disclose. © 2012 Lippincott Williams & Wilkins, Inc.