Functional data link the characteristic translocation (ASPL-TFE3) in ASPS to the ASPL-TFE3 fusion gene, which is shown to upregulate the expression of the c-MET receptor TK [15–19, 21, 22] Furthermore, MET has been revealed to be a direct transcriptional target of ASPL-TFE3. The gene discussed is TFE3; the disease is alveolar soft part sarcoma.