Cells possess an innate immune system that defends against invasive pathogens. Previous studies have mapped out the cytoplasmic cGAS-STING pathway in the cytoplasm, known for responding to foreign nucleic acids. The Fusion Visualization system 2 cell line was developed to visualize cellular nuclei with chromosome fusion and resulting micronuclei. Using FuVis2, researchers examined whether micronuclei influence the cGAS-STING response in live cells.