What is the relationship between term "Gene isoform" and "Protein isoform"?
Say a gene can make 3 isoforms, will it produce only (maximum) 3 isoform protein?
The term isoform has become a little ambiguous over the years (see http://blogs.cornell.edu/collinslab/2012/05/30/protein-isoform/)... still some things are consistent:
Note that databases will typically have a specific definition in mind for their use of isoform in their annotation, check their documentation for details (e.g. in UniProt see What is the canonical sequence? Are all isoforms described in one entry?)