Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2)[2] is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic.The nucleocapsid (N) protein is a protein that packages the coronaviruses to form ribonucleoprotein structures enclosed within the viral capsid. In addition to its interactions with RNA, N forms protein-protein interactions with the coronavirus membrane protein (M) during the process of viral assembly. N also has additional functions in manipulating the cell cycle of the host cell. The N protein is highly immunogenic and antibodies to N are found in patients recovered from SARS and Covid-19.