Coronaviruses have posed a global threat in three different periods over the past two decades. Severe Acute Respiratory Failure Syndrome (SARS-CoV) was first revealed in 2003. Then, in 2012, Middle East Severe Acute Respiratory Failure Syndrome (MERS-CoV) was detected. In late 2019, it was reported that Coronavirus 2 (SARS-Cov-2) was isolated from Severe Acute Respiratory Failure Syndrome. SARS-Cov-2, which causes a much more severe and common infection compared to SARS-Cov and MERS-Cov, remains a global threat until the vaccine is developed. Owing to the ongoing outbreak of SARS-Cov-2, many facts regarding virus-host interactions and pathogenesis of disease, still needed to be addressed in more detail.