PRNP and ocular melanoma: The RT-QuIC analysis has been recently developed and uses recombinant PrP (rec-PrP) as a reaction substrate and demonstrated the presence of PrPSc in the CSF, olfactory mucosa (OM), and skin of sCJD patients (Orrú et al., 2014, 2017; Franceschini et al., 2017; Mammana et al., 2020).