HK2 and glioblastoma: HK2 protein expression measured in 2 GBM cell lines (U87 and GS2) grown in 10% FBS and 4 primary GBM cultures grown in glioma stem cell media (GSC 8–18, GSC 7–2, TWH1, TWH2) exhibited on average 1.2 fold higher HK2 protein expression, although this was non-significant (Figure 1I, ns; p = 0.071).