Interestingly, astrocytes derived from newborn pups (RasB8p0) that are tumour free had markedly lower level of phosphorylated SHP2, which correlated with less SHP2 activity, compared with astrocytes derived from 3-month-old mice (RasB8p3) with GBM (Fig. 2a). This evidence concerns the gene PTPN11 and neoplasm.