CSPG4 and glioblastoma: Next, we investigated the requirement for NG2/CSPG4 recognition in NK+mAb9.2.27 therapeutic efficacy in U251-NG2 GBM tumors that stably overexpress rat NG2/CSPG4 but have a lower affinity for the human mAb9.2.27 as indicated by 34.5±4.2 % (n=3) positivity, (Supplementary Fig. 1B).