SMAD5 and glioblastoma: The systematic experiments demonstrated that (i) a higher BMP7/pSmad5 level is found in the human malignant glioma tissues compared to the healthy brain tissues; (ii) BMP7 promotes human LN18/LN229 glioblastoma cell transmigration and migration through autocrine stimulation; (iii) Smad5 increases the p75NTR level to regulate the BMP7 effect on human LN18 glioblastoma cell transmigration and migration; (iv) Smad1 gene knockdown in human LN18 glioblastoma cells directly initiate their cell death.