GLIPR1 and central nervous system cancer: To limit any positional effects of provirus, we then established polyclonal glioma cells with stable GliPR1 knockdown, by transducing three human glioblastoma cell lines (U87-MG, A172, U343-MG) with each of GliPR1 sh#301 and GliPR1 sh#258 using a constitutive retroviral-shRNA vector.