On immunohistochemistry, the tumour cells showed diffuse positivity for S100 protein (Figure 3A), and CD68 (Figure 3B); focal positivity for Inhibin (Figure 3C), and Bcl2 (Figure 3D); and were negative for SMA, Myogenin, HMB45, and GFAP. The gene discussed is MYOG; the disease is neoplasm.