However, no detectable PK-resistant PrP was observed in protein extracts treated with the enzyme in the Y218N and control-derived neurons generated with either protocol (Fig. 2d,h), in contrast to brain extracts from Y218N GSS or Type 1–2 CJD patients (Fig. 2h, Supplementary Fig. 2). Here, PRNP is linked to Creutzfeldt Jacob disease.