To identify other potential targets of Ezh2-dependent gene repression besides Olig2 that are related to SVZ NSC neurogenesis, we analyzed by expression microarray the transcriptional profiles of Ezh2Δ/Δ;Ink4a/Arf−/− and Control;Ink4a/Arf−/− SVZ NSCs across a differentiation timecourse (0, 1, 2, 4, and 7 d after differentiation). We used gene co-expression analysis (Zhang and Horvath, 2005; Oldham et al., 2008; Ramos et al., 2013), which organizes genes into modules that exhibit similar expression patterns, to analyze the expression data. (A) Top panels contain heatmaps representing the expression levels for three modules (saddlebrown, white, and darkgreen) of 46 co-expressed transcripts that, like Olig2, require Ezh2 for repression during neuronal lineage specification and would be expected to exhibit increased expression in Ezh2Δ/Δ;Ink4a/Arf−/− cells early in the differentiation time course, as compared to control cultures. Red = increased expression, Green = decreased expression, Black = no change. Bottom panels contain plots of the eigengene values in each module representing the first principal component of each module (‘Materials and methods’ for details of analysis). (B) Expression patterns for the top 15 genes ranked by their Pearson correlation to the first principal component of each coexpression module (Oldham et al., 2008) are shown. Samples on the x-axis correspond to those depicted in (A).