Thus far, three major signaling pathways have been identified as the most deregulated ones in glioblastoma, namely, the activation of the receptor tyrosine kinase (RTK)/Ras/phosphoinositide 3-kinase (PI3K) pathway and inhibition of the p53 and retinoblastoma protein (Rb) signaling pathways (The Cancer Genome Atlas Research Network, 2008 [1]). The gene discussed is TP53; the disease is glioblastoma.