Transcription factor E3 (TFE3) plays important roles in autophagy, lysosomal biogenesis and cellular stress responses [11], and serves as an oncogene in many tumor types with rearrangement at Xp11.2, including renal cell carcinomas, alveolar soft tissue sarcomas and perivascular epithelioid cell neoplasms [12, 13]. The gene discussed is TFE3; the disease is alveolar soft part sarcoma.