ALT, ATR, ATRX, ATRX mutations, Cancer, Cancer cells, Cell lines, High, High-Grade Solid Tumors, JHH-CRC65, JHH-NF1-GBM1 cell line, JHH-NF1-GBM1), MEK, MPNST, MPNST cell line, NF1, NF1 and ATRX deficiency, NF1)-associated, NF1-associated, NF1-associated ATRX mutant glioblastoma cell line, NF1-deficient MPNST, NF1-deficient MPNST cell lines, NF1-deficient and associated tumors, NF1-deficient sporadic glioblastomas, NF1-derived sarcoma cell line, NF90, Neurofibromatosis Type 1 (, SF188, ST88-14, TERC, U251, U251 cells, U251 glioma, U251 glioma cells, and, glioma, glioma cell line SF188, malignant, malignant solid tumors, solid tumors, telomeres, temozolomide