EA.hy926 cells are a somatic hybrid cell line widely used in cardiovascular disease research. They are used to study various aspects of endothelial cell function related to angiogenesis, homeostasis/thrombosis, blood pressure regulation, and inflammation. The cytoplasmic distribution of Weibel-Palade bodies and tissue-specific organelles in EA.hy926 cells observed by electron micrographs reflects their differentiated endothelial cell function. A key advantage of EA.hy926 cells is their ability to undergo more than 100 population doublings (PDLs) while maintaining their cellular properties. This long lifespan ensures a sustainable and consistent source of cells for long-term experiments and studies. With a doubling time of 12 hours, these cells exhibit rapid proliferation, facilitating experimental workflows and enabling efficient generation of cell numbers required for large-scale studies.