While an ORF4 could be observed in bat and camel viruses associated with HCoV-229E, alpaca alpha-CoV exhibits a single nucleotide insertion, resulting in a frameshift.
Huku ORF4 thabiti ikiwa na uwezekano wa kupatikana kwenye virusi vinavyopatikana kwenye popo na ngamia vinavyohusiana na HCoV-229E, virusi vya alpha-CoV vilivyopatikana kwenye alpaca vilionyesha kuwekwa kwa nukleotidi moja, kukisababisha kubadilika kwa fremu.