Both CD133 enriched and CD133– glioma cells are susceptible targets for BiAb-armed ATC. Cells from an ex vivo glioblastoma were separated into CD133– and CD133 enriched populations using magnetic separation (Miltenyi Biotec). The separated populations, stained with a CD133/2-specific MAb are shown in the inset. Unfractionated (Unfx) cells and CD133– and CD133 enriched populations were incubated overnight with unarmed ATC, or ATC armed with HER2Bi or CD20Bi, at an E:T of 3:1. The mean (± SEM) residual viability was determined using the MTT assay. Lower panel: Show the expression of HER2 and EGFR in CD133 enriched population from two ex vivo primary cells. Overall analysis by 1-way ANOVA, p < 0.0001. Individual comparison (Tukey-Kramer test): unarmed unfx vs. HER2Bi unfx p < 0.001 (***); unarmed unfx vs. CD20Bi unfx p > 0.05 ; unarmed CD133– vs. HER2Bi CD133–p < 0.001 (***); unarmed CD133– vs. CD20Bi CD133–p < 0.001; unarmed CD133+ vs. HER2Bi CD133+p < 0.05 (*); unarmed CD133+ vs. CD20Bi CD133+p < 0.01.