Interestingly, we did not register a complete deletion of the Ezh2 exon 14–15 using the RCAS-CRE system as detected by qualitative PCR, either in formalin-fixed paraffin embedded (FFPE) tumor tissues or in in-vitro cultured P3 neuronal precursors (Additional file 1: Fig. S1b, [34]). This evidence concerns the gene EZH2 and neoplasm.