Possible origin of SARS-CoV from recombination of different SL-CoVs

Despite the fact that Rs3367 or W1V1 is unprecedently close to SARS-CoV in terms of receptor-binding domain region and genome identity, still there are gaps between them and the immediate ancestor of SARS-CoVs. ORF8 is a highly variable gene and remarkable differences can be observed among SARS-CoV and SL-CoVs of different host origins.