What practical difference would it make, over the existing US sanctions, if Russia's PNTR status were revoked?

Apparently there's a difference of opinion between the White House and Congress on whether to revoke Russia's "permanent normal trade relations" (PNTR) with the US.

What practical difference would it make if the US revoked PNTR for Russia, given that e.g. US oil imports from Russia have been suspended and that Russia retaliated, apparently as much as it could against the US sanctions, by e.g. suspending sales of space rocket engines to the US. (This actually happened before the US move on oil.)

PNTR was granted to Russia relatively recently, in 2012. Apparently, it was done due to Russia joining the WTO that year.

Premise update: since I wrote the above, Biden announced that he does now support revoking PNTR, and that the other G7 countries have agreed to follow suit. Pelosi then announced new legislation to such effect to be introduced on the floor. Biden was somewhat vague on the concrete effects though:

"Revoking PNTR for Russia is going to make it harder for Russia to do business with the United States and doing it in unison with other nations that make up half of the global economy will be another crushing blow to the Russian economy that's already suffering very badly from our sanctions," Biden said.

So, I think my question is still relevant to a good extent.

I'm not entirely sure if this part of the PNTR move or just was announced simultaneously with it, but Biden also announced cutting off Russian seafood imports into the US, worth about $1.2 billion, annually.