TARBP2 and astrocytoma (excluding glioblastoma): Thus far, all human cell lines described express TRBP, but we have shown previously that U251MG, an astrocytoma cell line, expresses an undetectable amount of TRBP1 and a decreased amount of TRBP2 compared to HeLa or Jurkat cells [28,29] (Fig. 6A).