A) Schematic of the establishment of GBM recurrence model. B, C) There is an increased expression of various GSC subpopulations in GBM6 (B) and GBM43 (C) blue-tagged tumors, respectively, after primary chemotherapy (TMZ 2.5 mg/kg for 5 days treatment). PDX lines were implanted orthotopically and waited for 5 to 10 days for xenograft establishment. A dose of 2.5 mg/kg/day of TMZ was administering intraperitoneally for 5 days in tumor-bearing mice. We evaluated the status of the GSC population using flow cytometry in our animal groups: untreated vehicle, sacrificed 3 days post-completion of chemotherapy, and upon disease recurrence (determined by symptoms of disease). GSC subpopulations were indicated by single markers CD133+, CD15+, Sox2+ as well as co-expression of these markers CD133+Sox2+, CD15+Sox2+, or CD133+CD15+ compartments. The control group (DMSO) received DMSO. Error bars denote S.E.M. P: *P<0.05, **P<0.01, ***P<0.001, one-way analysis of variance.