SPP1 and prion disease: Relatively few transcripts of neural progenitors were differentially expressed (Fig. 2, cluster im.neu.24), although we noted the top overexpressed transcripts were Spp1 and Lpl, and the top underexpressed transcripts was Csmd3. We also identified 5 clusters of immature differentiating neurons, some of which appeared to increase or decrease in association with prion disease (Fig. 8B), although only cluster diff.neu.3 achieved statistical significance (increased in the cortex).