In the IHC study, tumor cells showed positivity for CD99 (Figure 3E), EMA (Figure 3F), vimentin, and TLE1, while they were negative for NKX2.2, WT1, BCOR, PDGFA, cytokeratins, muscle markers (smooth muscle actin, desmin, caldesmon, MyoD1, and myogenin), and melanocytic markers (HMB45, SOX10, and S100). The gene discussed is PDGFA; the disease is neoplasm.