Most coronaviruses invade cells much like other viruses, such as influenza, which merges its envelopes with the surface of unsuspecting cells to release genomes into the cell. Once inside, the viral genome is replicated and forms an army of new viruses. The newly formed influenza viruses assemble and bud from the cell surface, ready to invade other cells. However, coronaviruses take a different route of assembly and escape from their host cell. They use the pancakelike structure in cells, called the Golgi complex — a kind of post office for the cell that sorts and processes proteins and spits them out of the cell after enclosing the proteins in a compartment called a vesicle. Cell biologist Carolyn Machamer, Ph.D., has been studying how coronaviruses assemble in the Golgi body and then stow away in vesicles to be shipped outside of the cell.

This image reveals how tumor cells produce antigens that are captured by the immune system. Dendritic cells process these antigens and present them to the body's T cells, activating them. Once this process happens, the T cells multiply and locate the tumor, releasing factors to kill it.