A total of 5 Xp11.2 tRCCs have been identified in RCC tumors, PRCC-TFE3, ASPSCR1-TFE3, SFPQ-TFE3, NONO-TFE3, and CLTC-TFE3, all of which result in TFE3 (transcription factor binding to IGHM enhancer 3) gene fusions [3]. The gene discussed is TFE3; the disease is renal cell carcinoma.