Up-regulation of the MET-tyrosine kinase receptor, which in turn activates HGF-signaling, was detected in TFE-tRCC patients by in vitro assays (Tsuda et al., 2007), but subsequent analyses on TFE3-renal samples failed to identify activated MET protein (Kauffman et al., 2014). The gene discussed is HGF; the disease is renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions.