To generate cell lines carrying the MGMT fusions, we first transduced U251 and U87 cells, two MGMT-methylated GBM cell lines, with lentiviral vectors expressing different combinations of gRNA pairs directed to four different MGMT rearrangements: BTRC-MGMT, NFYC-MGMT, SAR1A-MGMT, and CTBP2-MGMT (Supplementary Fig. 2a–c). The gene discussed is BTRC; the disease is glioblastoma.