Proteins such as PKM and PDHA1 have been shown to play a prominent role in influencing cancer cell metabolism.36,37 Our data suggest that these enzymes are basally phosphorylated at a higher level in GBM39 than in GBM6 and GBM12, and may point to a broader metabolic signature predictive of response to EGFR TKIs. The gene discussed is PDHA1; the disease is cancer.