Measurement of CSF NSE and S100B has respective sensitivity values of 79%–85% and 65%–94% for sCJD, 0%–64% and 20%–87% for genetic prion diseases (gCJD, GSS, and FFI), and 52% and 78% for vCJD, while specificity values are 83–92% for NSE and 76%–90% for S100B. This evidence concerns the gene S100B and prion disease.