Immunohistochemically, the tumor cells were positive for melanoma-associated antigen (HMB-45), neuron-specific enolase, CD68, and transcription factor E3 (TFE-3), but negative for AE1/AE3, CAM5.2, epithelial membrane antigen, smooth muscle actin, Desmin, MyoD1, Caldesmon, Calponin, Synaptophysin, Chromogranin A, NCAM, Vimetin, CD34, S-100, Melan-A, CD99, CD10, D2-40, CD138, P-ALP, and multiple myeloma oncogene-1 (Figure 3ab). The gene discussed is TFE3; the disease is neoplasm.