SMAD4 and glioblastoma: An analysis of the expression profiling data of glioblastoma samples in The Cancer Genome Atlas database using Oncomine software showed a significant increase (3.271 fold) in the expression of SMAD4 (Reporter ID: 202527_s_at) mRNA in glioblastoma tissues (n=542) when compared with non-malignant brain tissue samples available in the database (Figure 3A) [39].