Within the Def CJD group, there was no significant difference of cystatin F levels between PrP type 1 and type 2 cases [35] (p = 0.14, Student’s t test, Fig 4E), nor between patients with 14-3-3 positive and negative results (p = 0.19, Student’s t test, Fig 4F). Here, PRNP is linked to Creutzfeldt Jacob disease.