Immunofluorescence of mice liver sections with nuclei (blue) and zonal markers E-cadherin (periportal, yellow) and glutamine synthetase (pericentral, red). The liver helps maintain metabolic processes, hormone production, nutrient storage, and detoxification. This happens when the oxygen and nutrient-rich blood flow from the periportal vein to the pericentral vein in the liver lobule, the functional unit of liver.  As a result, the blood flow creates a gradient of oxygen, nutrients and signaling molecules, creating three different zones in the liver lobule. These zones have different functions, and they express different proteins depending on their functions. Here, we have used Glutamine synthetase (red) to view the pericentral zone and E-cadherin (yellow) for the periportal zone to study the zonation.