The signalling protein ERK5 is essential for maintaining normal endothelial cell function.

Endothelial cells may be infected within 3 days after exposure to the virus.

Once infected, endothelial cells (cells lining the inside of blood vessels), liver cells, and several types of immune cells such as macrophages, monocytes, and dendritic cells are the main targets of infection.

Types There are three main types of blood capillaries Continuous Continuous capillaries are continuous in the sense that the endothelial cells provide an uninterrupted lining, and they only allow smaller molecules, such as water and ions to pass through their intercellular clefts.