NOTCH1 and neoplasm: This hypothesis is supported by an in vivo CRISPR screen that identified Notch1 among potential tumor suppressors in glioma [41], and is further in line with the occurrence of NOTCH1, NOTCH2, and RBPJ inactivating mutations and/or reduced Notch signaling activity in human glioma subtypes [21,23,26,27,28,29,30,31].