Jose et al. [5] investigated The Cancer Genome Atlas (TCGA) data and found that the level of pyruvate carboxylase was higher in human gliomas containing the IDH1 mutation than in those with wild-type IDH1. The fractional flux, which depends on the activity of pyruvate carboxylase, is therefore increased in cells with the IDH1 mutation. The gene discussed is PC; the disease is glioma.