Immunostains on tumor biopsy were positive for SMA and calretinin (focal in epithelioid nests) and negative for cytokeratins (Ck-AE1/AE3 and CK5/6), TTF-1, mammaglobin, breast gross cystic disease fluid protein-15, estrogen/progesterone receptors, CD34, and desmin. The gene discussed is DES; the disease is neoplasm.