USP4 knockdown in glioblastoma hindered cell proliferation and induced tumor cell apoptosis through inactivating canonical TGF-β signaling pathway (TβRI/pSmad2) and non-canonical TGF-β signaling pathway (TβRI/phosphorylated extracellular regulated protein kinases1/2). The gene discussed is TGFBR1; the disease is glioblastoma.