MRC1 and Insulin resistance: Upon overnutrition, ATMs have been reported to switch from type 2 (M2; CD11c−CD206+) to type 1 (M1; CD11c+CD206−) polarization states, promoting local and systemic inflammation and insulin resistance.[3, 6, 7] However, the identification of balanced M0 (CD206−CD11c−)[8] and mixed (CD206+CD11c+)[9] phenotypes indicates the existence of additional subtype diversity.[10, 11] Targeting of maladaptive adipose tissue macrophage (ATM) phenotypes has the potential to restore the function of ATMs for the homeostasis of adipose tissue in obese individuals.