This is an interesting copolymer variant in that one of the ingredients was a polymer to begin with.

And because these materials are so prolific, because they're found in so many places, there's one other place you'll find this material, styrene, which is made from benzene, a known carcinogen.

PFK exists as a homotetramer in bacteria and mammals (where each monomer possesses 2 similar domains) and as an octomer in yeast (where there are 4 alpha (PFK1) and 4 beta chains (PFK2), the latter, like the mammalian monomers, possessing 2 similar domains).