DHX9 and glioblastoma: In order to extend the pathway regulated by circSMARCA5 to upstream signals, we investigated the expression of: (i) circSMARCA5, (ii) mRNA of its negative regulator DHX9 (see Discussion), and (iii) Iso8a and Iso8b VEGFA mRNA isoforms in a cohort of 28 GBM tumor biopsies.