GABBR1 and glioblastoma: GB1, DKMG, and NP5 were among the CCLE glioblastoma cell lines with the highest PDE3A and SLFN12 expression, consistent with prior reports (Figure 1F).11 Next, we compared PDE3A and SLFN12 expression in the CCLE cell lines with expression values from primary gliomas from the Cancer Genome Atlas (TCGA; Figure 1F, Supplementary Table 1).