GBM8401 cells were established and characterized by Dr. Lee of our medical center in 1988 [46]; hence, our team will further characterize different molecular characteristics of patient-derived GBM cell lines to understand the functional role of TELO2 in the status of telomere length differentially regulated by the TERT promoter mutation, ALT pathways, or other molecular targets verified in GBM patients. The gene discussed is TELO2; the disease is glioblastoma.