In terms of Prions is there a possibility, that other proteins apart from PRPC could be misfolded
There are many prions other than PrP; it is often helpful to e.g. read wikipedia for these cases.
For example, there are many yeast prions that are not homologous to PrP https://en.wikipedia.org/wiki/Fungal_prion.
But even in humans there are a number of other proteins that form amyloids and are described as &quot;prion-like&quot; even though they aren't the canonical protein: https://en.wikipedia.org/wiki/Prion#In_other_diseases