Proliferation of glioma cells has been correlated to CREB activation [28], and since CD44 signalling is important for sustaining active CREB [29], we analysed the phosphorylation status of S132 in CREB by immunoblotting; dramatically reduced p-CREB levels were detected in CD44 KO clones in comparison to control cells, both in the presence and absence of serum (Figure 1e). This evidence concerns the gene CREB1 and central nervous system cancer.