Figure 3. Microscopic features of the primary tumor and xenograft. (A) Histopathological features of the primary tumor (HE staining, magnification × 200). (B) Immunohistochemistry for TFE3 in the primary tumor shows strong nuclear staining (magnification × 200). (C) Interphase FISH analysis of the primary tumor with a dual-color, break-apart DNA probe. The TFE3 probes were labeled green at the centromeric site and orange at the telomeric site. Split signals are observed (arrows).