Immunohistochemically, >80% of the tumor cells demonstrated strong positivity for HMB45 (cytoplasmic), Melan-A (cytoplasmic) and smooth muscle actin (membranous), while smooth muscle myosin heavy chain, desmin and CD117 were weakly positive in <20% of the tumor cells (Figures 2 &3). The gene discussed is PMEL; the disease is neoplasm.