Among the commonly used immunohistochemical markers, CA9 and cytokeratin 7 are the most helpful immunostainings for differentiating TFE3-rearranged renal cell carcinoma from common renal cell tumors as they are frequently negative in TFE3-rearranged renal cell carcinoma [46]. The gene discussed is CA9; the disease is hereditary clear cell renal cell carcinoma.