Clinical relevance of putative TWIST1 in vitro target genes: SNAI2 and FAP were identified as putative TWIST1 target genes in SNB19 and/or T98G cells. The expression of SNAI2 (A) and FAP (B) are highly correlated with TWIST1 expression in a group of 39 glial tumors of different grade and type including 9 grade II, 3 grade III and 27 grade IV (21 GBM, 6 gliosarcoma (GS) [open circles]) gliomas. ΔCt (dCt) values were determined by qRT-PCR. Correlation coefficients and p values are shown in insets. (C, D, E) The expression levels of TWIST1, SNAI2 and FAP relative to normal brain in different grades of glioma (II+III vs IV) and in the grade IV sub-types (GBM and gliosarcoma (GS)) are shown. Expression of TWIST1, SNAI2 and FAP are higher in grade IV gliomas (GBM and GS) compared to grades II and III combined (p = 0.022, p = 0.0014, p = 0.005, respectively). Analysis of grade IV tumors demonstrated higher levels of TWIST1, SNAI2 and FAP expression in GS compared to GBM (right side of each expression panel) (p = 0.0003, p = 0.0001, p = 0.0014, respectively). Horizontal bars show mean value of expression for each group of tumors. (*, ** p < 0.05). Statistical analysis was performed using log transformed relative expression values.