TGFBR2 and glioblastoma: Glioblastoma-derived CTCs present with EGFR amplification, which is linked to aggressiveness and the presence of EGFRvIII, and higher levels of SERPINE1 (serpin family e member 1), VIM (vimentin), TGFB1(transforming growth factor beta 1), and TGFBR2 (transforming growth factor beta receptor 2) genes, which are linked to the mesenchymal subtype [135,139].