In the past decade, sorafenib, multi-kinase inhibitor [against vascular endothelial growth factor receptor (VEGFR)1-3, fms-like tyrosine kinase 3, RET and RAF kinases, platelet-derived growth factor (PDGF) and KIT], has crucially contributed to the systemic therapy of patients with advanced or metastatic hepatocellular carcinoma (HCC) or clear cell carcinoma of the kidney 3, 4. This evidence concerns the gene RET and hepatocellular carcinoma.