We analyzed the gene expression profile of NPCs throughout the differentiation stages by time-lapse analysis using STEM software. We found 16 modules of genes including more than 30 000 genes that were enriched in NPCs. The 16 modules can be divided into three groups by trends of expression level. Of the 16 modules, 8 showed statistically a significant difference. The three groups were a decreasing (2 modules) group, increasing (4 modules) group, and disorder-associated (2 modules) group (Fig. 7).
