SMAD2 and glioblastoma: Inhibited the proliferation, stemness, migration, and invasion of glioblastoma cells,Inducing apoptosisRestraining the progression of xenograft tumorsDecreasing the expression of Bcl-2 (an antiapoptotic marker) (2–8 μM of chelerythine)Increasing the expression of Bax (a pro-apoptotic marker) in glioblastoma cells (2–8 μM of chelerythine)Reducing the protein expression of p-ERK1/2 and p-Smad2/3 in a dose-dependent manner