Consistent with this finding, LN229 and SF188 glioblastoma cells treated with ABT263 in the presence of 2-HG show a markedly enhanced cleavage of caspases 9, 3, and PARP, supporting the relevance of apoptosis as mechanism of the synergistic anti-cancer activity (Fig. 2j). Here, CASP9 is linked to glioblastoma.