In addition to the well-known SARS-CoV, MERS-CoV, as one Merbecovirus subgenus of β-CoVs, is also extremely invasive. MERS-CoV is the pathogen of the Middle East Respiratory Syndrome, which can infect both humans and animals, and can be transmitted through camels [109]. It mainly occurs in Saudi Arabia and has a high mortality rate [66]. Studies had demonstrated that the clinical course of SARS and MERS was highly similar, and SARS and MERS may have similar pathogenesis [66]. The genome sequence of SARS-CoV-2 also shows some similarities to that of MERS-CoV. It will be very interesting to study the relationship among SARS-CoV, MERS-CoV, and SARS-CoV-2 that may be exploited for future developing broad-spectrum antiviral therapies.