Coronaviruses (CoVs) are a diverse family of viruses that interact at multiple levels with components of host cells taking this advantage of some of the cellular machineries for replication and proliferation. Various are known about the molecular biology of CoVs but more information is needed to learn. For example, many of the non structural  and accessory proteins encoded by these viruses remain uncharacterized with no known function, and it will be important to identify mechanisms of action for these proteins as well as defining their role in viral replication and pathogenesis.