L1CAM and glioblastoma: In glioblastoma CSCs, L1CAM enhanced DNA damage response (DDR) checkpoints and repair, whereby radiation-induced nuclear translocation of the L1CAM intracellular domain upregulated expression of proto-oncogenes c-Myc and NBS1, which are critical components of the MRE11–RAD50–NBS1 (MRN) complex that activates signaling of ataxia telangiectasia mutated (ATM) kinase [14].