IDH1 and chondrosarcoma: Alanine (Ala), glycine (Gly), and serine (Ser), which are broadly elevated in mutant IDH chondrosarcomas (Fig. 2d, Table 2), enter pathways of energy production via pyruvate, which in turn can be oxidized via pyruvate dehydrogenase or used as an anaplerotic substrate to generate oxaloacetate via pyruvate carboxylase.