TFE3 and renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions: Immunohistochemical features of TFE3-tRCC are characterized by a specific strong nuclear expression of TFE3 (antibody targeting the c-terminal portion of TFE3) sometimes associated with positive cathepsin K (approximately 60% of cases) (Figure 1).