STAG2 and Ewing sarcoma: STAG2 mutant glioblastoma, Ewing sarcoma and hTERT-positive retinal pigmented epithelial cells are sensitive to several DNA alkylating agents (cyclophosphamide, gemcitabine and temozolomide), ATR kinase inhibitors (VX-970, AZD6738), topoisomerase poisons (doxorubicin, etoposide and topotecan) [15].