Novel 3D maps show how genes interact in several types of immune cells The COVID-19 pandemic has highlighted how our small genetic differences can have a tremendous effect on how our bodies respond to disease. The difference is within us. We can get infected by the same bacteria or viruses, but the ways our diseases progress can be very different." Vivek Chandra, Ph.D, Instructor at La Jolla Institute for Immunology Genetic variations are important, but there's more to the puzzle. To truly understand how genes affect health, researchers need to track down the switches (also called "enhancers") that control when and where a gene is expressed in the body.