Summary The Mouse Breeding and Procedure Core (Core C) is essential for the smooth functioning of the Program Project. Core C has two major functions. First, Core C will provide and oversee mouse breeding and genotyping services. Mice will be bred centrally for all three projects of the Program Project in order to maximize quality control and consistency of mouse lines, and to maximize efficiency, particularly for lines shared across the three Projects. Mice will be mated, born, separated, and weaned by the Core members. The Core will direct tails for genotyping to NYU Core for Genotyping Services. Once genotyped, Core C will allocate mice to either further breeding or to experimentation depending on the needs and the genotype/sexes of mice obtained. Core C will distribute all mice for studies to the three Projects by age 6 weeks. As indicated in the individual Projects, Core C, through Core A, implements randomization and strategies that will be essential for rigor and reproducibility and protection against bias. Second, Core C will coordinate and perform mouse procedures. Shared procedures across the Program Project to be performed and overseen by Core C include: aorta transplantation surgery, lethal irradiation and bone marrow transplantation; adipose tissue transplantation; parabiosis; glucose and insulin tolerance tests; imaging studies (liver ultrasound and magnetic resonance imaging and DEXA scanning); isolation of primary cells from the liver, including hepatocytes, Kupffer cells and hepatic stellate cells and isolation of extracellular vesicles. Core C will serve all three projects of the Program Project over all five years.