To genocopy PTEN loss, the PTEN WT glioblastoma cell line LN-229 was subjected to CRISPR/Cas9-mediated genome editing and resulting clones were inspected for PTEN levels and activity, respectively, as witnessed by PTEN and phospho-AKT levels under low-serum conditions (Fig. 5b). Here, PTEN is linked to glioblastoma.