et al., 2014; Fehr and Perlman, 2015; Tomar et al., 2015; Snijder et al., 2016). In addition to the genes encoding the above structural proteins, the genes encoding accessory proteins have also been detected in the 3′ region between S–E–M–N (Fehr and Perlman, 2015). Some beta-CoVs, such as HC