Overexpression of 3-phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme in the biosynthesis of serine from glucose, has been observed in many cancer types and has been linked to poor patient outcomes including chemotherapy resistance, shorter progression-free survival, increased rates of metastasis and poorer overall survival (reviewed in [67]). The gene discussed is PHGDH; the disease is cancer.