They reported that AKT1 mutations were detected only in metastases and that different metastases from the same individual could exhibit PIK3CA mutations or AKT1 mutations, leading them to suggest that defects in the PI3K/Akt pathway occur during tumor progression, and that use of primary cancer material to stratify patients for specific therapies may not be the most effective strategy. The gene discussed is PIK3CB; the disease is cancer.