CD109 and glioblastoma: We first detected the expression level of the four ER lncRNAs (AC131097.3, CD109-AS1, LINC02447, and LINC01765) in two GBM cell lines (U251 and U87) by qRT-PCR assays, and found that CD109-AS1 and LINC02447 were highly expressed in both cell lines while the AC131097.3 and LINC01765 were shown to undergo deletion (Figure 6A).