Comparison of fNSCs and BTSCs. Human fetal neural stem cells were used as model for the normal precursor cells for BTSCs. A. (left) Example of gain of H3K4me3 mark in a promoter in all four BTSC lines, as compared to fNSCs. (right) Example of loss of H3K27me3 mark in all four BTSC lines, as compared to fNSCs. Left axis is log2 enrichment ratio. All displayed transcripts extend beyond edge of figure area. B. Explication of comparison of fNSC promoter sets to BTSC promoter sets by epigenetic mark. “Universe” and “core” sets as in Figure 2. fNSC is left circle in each case. Critical computations in diagram are indicated in bold, italic, underlined font. C. Results of comparison of fNSC and universe or core BTSC sets for each epigenetic mark.