Hi guys, if we want to use human coronaviruses to do some bioinformatics analysis, it will be the best to retrieve sequences/genomes from human host? Or it doesn't matter?

This is because I got the deposited data file of all human coronaviruses sequences from a published article from PNAS, and I realised small number of the sequences retrieved are not from human host or they are from unknown host. I am confused whether human coronaviruses genomes/sequences must be from human host. Can any experts or professionals explain to me about this matter?

When I'm downloading the sequences and sequences information from NCBI database, I managed to check the host of that particular sequence/genome.

Thank you in advanced for all the explanations :)